Macamides

Macamides: A Comprehensive Reference Article

1. Identity and Chemical Nature

1.1 Botanical Source and Taxonomic Context

Macamides are a distinct class of secondary metabolites that have so far been found only in Lepidium meyenii Walp. (Maca). Macamides and macaenes are assumed to be the characteristic marker compounds of Maca, as they have not been found in any other plants.

Lepidium meyenii (maca) is a Peruvian plant of the Brassicaceae family cultivated for more than 2000 years, which grows exclusively in the central Andes between 4000 and 4500 m altitude. The plant is also referenced in research literature under the alternative taxonomic name Lepidium peruvianum Chacón. Peruvian maca is known internationally under its scientific name Lepidium meyenii Walpers — the name in use since 1843 when German botanist Gerhard Walpers deposited the first specimen-holotype of this plant in the Herbarium of San Marcos University (SMU) in Lima. In 1960, Peruvian botanist Gloria Chacón-Roldán described maca under the alternative name Lepidium sp., but it was not until 1990 that she deposited in the same herbarium a holotype under the new scientific name Lepidium peruvianum Chacón.

The plant is grown for its fleshy hypocotyl that is fused with a taproot, which is typically dried but may also be freshly cooked as a root vegetable. Maca grows at high altitudes in the Peruvian Andes mountain range (3500–5000 m).

1.2 Chemical Definition and Structure

Macamides are a distinct class of secondary metabolites — benzylamides of long-chain fatty acids — which were isolated from the Peruvian plant Lepidium meyenii (Maca). More precisely, macamides are a unique series of non-polar, N-benzyl, long-chain, fatty acid amides, and are responsible for the predominant biological activity of Maca.

Macamides are a series of long-chain fatty acid N-benzylamides, which were formed by one benzylamine or 3-methoxybenzylamine and one fatty acid through an amide bond. The fatty acid component varies in chain length and degree of unsaturation, giving rise to the diversity of individual macamide structures observed in the plant.

1.3 Principal Individual Compounds

Using HPLC-UV-MS/MS, the main macamides have been identified as N-benzylhexadecanamide, N-benzyl-(9Z)-octadecenamide, N-benzyl-(9Z,12Z)-octadecadienamide, N-benzyl-(9Z,12Z,15Z)-octadecatrienamide, and N-benzyloctadecanamide.

Up to 27 types of macamides have been identified. One of the most biologically active macamides is N-benzyl-(9Z,12Z)-octadecadienamide (also called N-benzyl-linoleamide; PubChem CID: 68742556), possessing various biological activities, such as anti-fatigue, neuroprotective, antioxidant, anti-tumoral, anti-inflammatory, and analgesic activities.

A survey of commercial products identified eight reference macamides: N-(m-methoxybenzyl)-9Z,12Z,15Z-octadecatrienamide (M1), N-benzyl-9Z,12Z,15Z-octadecatrienamide (M2), N-(m-methoxybenzyl)-9Z,12Z-octadecadienamide (M3), N-benzyl-9Z,12Z-octadecadienamide (M4), N-(m-methoxybenzyl)-hexadecanamide (M5), N-benzyl-hexadecanamide (M6), N-benzyl-9Z-octadecenamide (M7), and N-benzyl-octadecanamide (M8).

N-benzylhexadecanamide is the most abundant compound in Maca from Peru, while N-benzyl-9Z,12Z-octadecadienamide is the richest compound in Yunnan Maca.

1.4 Structural Relationship to Endocannabinoids

As structural analogues of the endocannabinoid anandamide (AEA), macamides have demonstrated neuroprotective effects in vitro and in vivo. This structural kinship is a defining feature that underlies much of the current mechanistic research into how macamides interact with mammalian biological systems.

2. Biosynthesis and Formation: The Critical Role of Postharvest Processing

HPLC analyses show that macamides are absent in fresh undamaged Maca tissues, while the hypocotyls dried by traditional Andean post-harvest practices or by an industrial oven contain up to 800 µg g⁻¹ dry weight of macamides. This means macamides are not truly pre-formed plant constituents in the conventional sense, but rather arise as products of post-harvest biochemical reactions.

Analysis of the macamide biosynthetic pathway suggests that glucosinolate catabolism, lipid hydrolysis, and amide formation are key steps controlling macamide accumulation in the tissues during the postharvest drying process.

Macamides are a series of long-chain fatty acid N-benzylamides formed by one benzylamine or 3-methoxybenzylamine and one fatty acid through an amide bond. Benzylamine and 3-methoxybenzylamine are conversion products formed during degradation of glucosinolate, while free fatty acids are hydrolysis products of membrane and storage lipid.

Macamides are synthesized via the reaction of benzylamine or its substitutes and long-chain fatty acids catalyzed by enzymes during the drying process. Long-chain fatty acids are the precursors of macamides.

All available results indicate that macamide biosynthesis is a long and sustaining reaction, which started from the drying process and continued during storage. In addition, the generation of macamides is slow even though the biosynthetic precursors — free fatty acids and benzylamine — are sufficient.

The method of drying has a substantial effect on the final macamide yield. Freeze drying can efficiently decrease drying time, but it concurrently interrupts the biosynthetic pathway of macamides. By contrast, the air-drying method can increase the accumulations of macamides and fatty acids in the metabolism of maca in the postharvest process.

Significant variations in macamide content have been found in commercial products surveyed (69–2738 µg/g). Meanwhile, the amount of macamides in dried plant material from different vendors has been reported to range from 0.0016 to 0.0123% in earlier analytical studies, with later quantification methods yielding a broader range depending on processing conditions.

3. Natural Source, Ecotypes, and Preparations

3.1 Plant Ecotypes and Color Variants

Research over the last twenty years has identified up to seventeen different colors (phenotypes) of maca. The color, hypocotyl size, growing location, cultivation, and post-harvest processing methods can have a significant effect on the nutrition content, phytochemical profile, and clinical application.

Fatty acids and macamides were higher in spray-dried extracts of black maca than in red maca. This variation has implications for the therapeutic activity attributed to specific maca phenotypes.

3.2 Commercial Forms and Preparations

Maca is exported as powder, capsules, pills, flour, liquor, and extracts. As a cash crop, it is primarily exported as a powder that may be raw or processed further as a gelatinized starch or as an extract. If dried, it may be processed into a flour for baking or as a dietary supplement.

Currently, maca dietary ingredients comprise a wide range of ingredients including maca root powder, maca root gelatinized powder, and different types of maca root extracts purified to specific groups of bioactive compounds in maca (i.e., glucosinolates, macamides, or amino acids), the latter ones requiring further evaluation for possible risk to health. Individual USP-NF quality monographs for these articles, including specifications, testing, and accepting criteria for the identity, composition, purity, and limits of contaminants, are currently in development.

4. Traditional and Historical Use

4.1 Pre-Columbian and Andean Use

Lepidium meyenii Walp., a species of the family Brassicaceae, has been cultivated both as a crop and medicinal plant for 1300–2000 years in Peru.

Maca is an annual herbaceous plant native to the high plateaus of the Peruvian central Andes. Its underground storage hypocotyls have been a traditional medicinal agent and dietary staple since pre-Columbian times. Reported properties include energizing and fertility-enhancing effects.

Peruvian maca is a centuries-old South American medicinal herb restricted in distribution to high Andean plateaus above 4,000 m a.s.l., and has been traditionally used by indigenous Peruvians as a vital dietary supplement and an important staple food component in their diet. This ancient plant cultivated by natives since Inca times is believed to have favorable effects on energy and mood, fertility, improving sexual desire, and decreasing anxiety.

Maca has been used for centuries in the Andes for nutrition and to enhance fertility in humans and animals. Traditionally, the Andean people used maca as food or medication to treat respiratory conditions and rheumatic disease.

4.2 Traditional Preparation

The Peruvian native population in the central Andes uses the hypocotyls after they have been naturally dried, in amounts greater than 20 g per day. Natives from the highlands of Peru recommend that maca be boiled before its consumption because fresh maca may have adverse effects on health.

It is significant, from a phytochemical perspective, that traditional practices of slow, open-air drying are precisely the conditions that promote maximal macamide biosynthesis. The macamide content of maca is therefore an artifact, in part, of the traditional Andean post-harvest technique — the very preparation method used medicinally for centuries.

4.3 Historical Documentation

Over the past 20 years, interest in maca has increased in many parts of the world, and since 2005 maca is considered one of the seven Peruvian flag products. This review summarizes the current state of knowledge on Lepidium meyenii (maca), a cruciferous plant (Brassicaceae family) which is cultivated exclusively at an altitude of 4,000–4,500 m in the Peruvian Central Andes.

5. Key Constituents and Active Compounds

While macamides are the subject of this article, they exist in the context of a broader phytochemical profile. Many components obtained from Maca have been screened for their bioactivities, such as non-starch polysaccharides, glucosinolates, thiohydantoins, phytosterols, polyphenols, and alkaloids. Maca's chemical composition varies due to ecotypes, growth conditions, and post-harvest processing, contributing to its intricate phytochemical profile, including macamides, macaenes, and glucosinolates, among other components.

Among all these constituents, macamides are a unique series of non-polar, N-benzyl, long-chain, fatty acid amides, and are responsible for the predominant biological activity of Maca.

More than thirty macamide monomers have been identified in recent years; however, it is difficult to obtain a single macamide monomer from the maca plant because of their similar structures and characteristics.

6. Established Mechanisms of Action

6.1 Inhibition of Fatty Acid Amide Hydrolase (FAAH)

The best-characterized mechanism of macamide action is inhibition of the enzyme fatty acid amide hydrolase (FAAH). The FAAH enzyme is responsible for endocannabinoid degradation in the nervous system. Previous studies have demonstrated the activity of the pentane extract and its macamides, the most representative lipophilic constituents of Maca, in the endocannabinoid system as FAAH inhibitors. One of the most active macamides, N-3-methoxybenzyl-linoleamide, was studied to determine its mechanism of interaction with FAAH and whether it has inhibitory activity on monoacyl glycerol lipase (MAGL), the second enzyme responsible for endocannabinoid degradation.

Four macamides were tested at concentrations between 1 and 100 μM, utilizing an FAAH inhibitor screening assay. The results demonstrated concentration-dependent FAAH inhibitory activities for the four macamides tested. N-Benzyloctadeca-9Z,12Z-dienamide demonstrated the highest FAAH inhibitory activity, whereas N-benzylstearamide had the lowest inhibitory activity.

Macamides have demonstrated inhibitory activity of FAAH. Eleven of the 19 reported macamides were synthesized and tested as potential inhibitors of the human enzyme FAAH; the five most potent macamides were FAAH inhibitors (IC50 = 10–17 μM). These amides were derivatives of oleic, linoleic, and linolenic acids and benzylamine or 3-methoxybenzylamine.

Macamide concentrations from 1 to 100 μM were tested using FAAH and MAGL inhibitor assay methods and showed no effect on MAGL. This indicates that macamide activity is selective for FAAH over MAGL in vitro.

6.2 Endocannabinoid System Modulation and CB1/CB2 Receptor Activity

One of the most studied processes of the endocannabinoid system is the role that the FAAH enzyme has in the degradation of anandamide or arachidonoylethanolamide (AEA), one of the main endocannabinoids synthesized by the body. AEA is a neuromodulator through its agonist or activator effect on CB1 and CB2 receptors. In addition, this endocannabinoid is vital in creating memory and sensations such as hunger, sleep patterns, and pain relief.

The neuroprotective activity of the macamides N-(3-methoxybenzyl)oleamide (MAC 18:1), N-(3-methoxybenzyl)linoleamide (MAC 18:2), and N-(3-methoxybenzyl)linolenamide (MAC 18:3) was demonstrated in a neurotoxic environment caused by exposure of U-87 MG glioblastoma cells to manganese chloride (MnCl₂). The neuroprotective effects of these macamides were reversed by the CB1 antagonist AM251. This reversal by a CB1 antagonist provides direct mechanistic evidence that the neuroprotective action involves CB1 receptor engagement.

6.3 PPARγ Activation

In a manner similar to the analogous endocannabinoid AEA, macamides interact with other targets such as PPARγ to regulate metabolism and energy homeostasis, cell differentiation, and inflammation. Human peroxisome proliferator-activated receptor gamma (PPARγ) has been proposed to be a cannabinoid target. PPARγ activation was observed in response to exposures of cells to MAC 18:2 and MAC 18:3.

6.4 Anti-inflammatory Pathways

Significant decreases in pro-inflammatory factors and reactive oxygen species (ROS) contents were observed in mice receiving N-benzyl-(9Z,12Z)-octadecadienamide treatment after a 30-minute swimming test, which was equivalent to that of caffeine. Macamides mitigate ROS produced by the mitochondrial respiratory chain that accumulates in skeletal muscle, reversing fatigue and oxidative damage to cells.

6.5 GPCR Modulation

Macamides have been shown to have agonist activity and to modulate the function of GPCRs associated with neurological disorders. Of particular note are several studies showing that the macamide N-benzyl-9Z,12Z-octadecadienamide has a high affinity with GPCRs and exerts therapeutic effects in neurological contexts.

6.6 Anticonvulsant Mechanism

Experimental evidence suggests that epileptic neurons are linked to the endocannabinoid system and that inhibition of the FAAH enzyme could have neuroprotective effects by increasing the levels of endogenous endocannabinoid anandamide. The use of macamides as therapeutic agents in neurological diseases has increased in recent years. With a similar structure to anandamide, several theories point to the FAAH–macamide interaction as a possible cause of FAAH enzymatic inhibition.

7. Scientific Evidence by Area of Use

Important context: The health claims of Maca are not fully supported by functional studies and clinical trials. The vast majority of research on macamides as isolated or semi-purified compounds is preclinical — conducted in cell culture models and animal studies. Human clinical trials have generally studied whole maca root preparations, not macamide isolates, making it difficult to attribute specific outcomes definitively to macamides alone. Chemical profiling led to the discovery of new compounds unique to maca, such as macamides, and also other active metabolites like the glucosinolates, to which the medicinal effects of maca have been ascribed, but which cannot be confirmed due to lack of data.

7.1 Neuroprotection and Neurological Disorders

Preclinical/In vitro evidence (preliminary to moderate strength):

Recent years have seen an increase in exploration of the therapeutic effects of various metabolites extracted from Maca. Among the most important secondary metabolites contained in this plant are macamides, molecules derived from N-benzylamides of long-chain fatty acids. Macamides have been proposed as active drugs to treat some neurological disorders. Their excellent human tolerance and low toxicity along with neuroprotective, immune-enhancing, and antioxidant properties make them ideal for exploration as therapeutic agents.

The mechanism by which manganese (Mn) induces cell damage was investigated by studying its effects on mitochondria. Reactive oxygen species (ROS) increase intracellular calcium and enhance the opening of mitochondrial permeability transition pores (MPTP), which leads to decreased mitochondrial membrane potential (MMP), disruption of mitochondria, and neuron death in neurodegenerative disorders. In this study, MnCl₂ at 50 μM was responsible for mitochondrial disruption, which was attenuated by all three of the macamides tested.

Reactive oxygen species (ROS) increase intracellular calcium and enhance the opening of mitochondrial permeability transition pores (MPTP), which leads to decreased mitochondrial membrane potential (MMP), disruption of mitochondria, and neuron death in neurodegenerative disorders.

The mechanisms of N-benzyl-(9Z,12Z)-octadecadienamide (M 18:2) in improving cognitive impairment were studied using a scopolamine-induced mouse neural injury model. Additionally, 16S rRNA sequencing was used to study the effect of M 18:2 on gut microbiota. This study links macamide activity to the gut-brain axis, though the findings remain preclinical.

The neuroprotective effects of maca were reported in 11 preclinical studies. In vitro studies have evaluated different maca formulations such as extracts, isolated compounds (macamides), polysaccharide fractions, and glucosinolates.

Human/clinical evidence: No well-designed human clinical trials have investigated maca's effects on cognitive function, memory, or neuroprotection. Broader systematic reviews mention neuroprotection as a potential benefit, but the evidence remains limited to preclinical data.

Summary of evidence strength: Neuroprotection by macamides is a promising area with a growing body of in vitro and animal data, but no human clinical trial evidence exists for macamides as isolated compounds. Evidence must currently be characterized as preliminary.

7.2 Sexual Function and Fertility

Preclinical evidence: Animal experiments suggest that maca has spermatogenic and fertility-enhancing activities. Several in vivo studies have shown that maca may improve sexual behaviour and enhance androgen-like effects in rats.

Clinical/human evidence (limited, mixed):

A systematic review published on PubMed and indexed in the DARE database found: Four RCTs met all inclusion criteria. Two RCTs suggested a significant positive effect of maca on sexual dysfunction or sexual desire in healthy menopausal women or healthy adult men, respectively, while the other RCT failed to show any effects in healthy cyclists. The further RCT assessed the effects of maca in patients with erectile dysfunction using the International Index of Erectile Dysfunction-5 and showed significant effects.

However, the review's authors were explicit about the quality limitations: The results of the systematic review provide limited evidence for the effectiveness of maca in improving sexual function. The total number of trials, the total sample size, and the average methodological quality of the primary studies were too limited to draw firm conclusions. More rigorous studies are warranted.

Maca increased seminal volume, sperm count per ejaculum, motile sperm count, and sperm motility in 9 healthy men (24 to 44 years of age) treated over 4 months with gelatinized maca root 1,500 or 3,000 mg/day. Serum hormone levels of luteinizing hormone, follicle stimulating hormone, prolactin, testosterone, and estradiol were not modified with maca treatment.

14 days of maca extract supplementation improved 40 km cycling time trial performance and sexual desire in trained male cyclists.

Summary of evidence strength: Clinical evidence for maca and sexual function is limited in sample size and methodological quality. These studies examined whole maca preparations; the specific contribution of macamides to sexual function outcomes in humans has not been isolated in clinical trials.

7.3 Physical Endurance and Anti-Fatigue Effects

Preclinical evidence (moderate, animal models):

Maca has been used as a food or folk medicine to improve vitality in Peru. Previous research demonstrated that lipid-soluble extract from maca improved swimming endurance capacity. Macamides are considered the typical lipid-soluble markers for maca and proved to have several pharmacological properties, such as improving sexual performance and neuroprotective activities.

A controlled animal study administered macamides at two dose levels: Balb/c mice were divided into seven groups: a control group, low-dose groups of N-benzyllinoleamide, N-benzyloleamide, and N-benzylpalmitamide, and high-dose groups of these macamides. The macamides groups received the commercial products (12 and 40 mg/kg, ig), while the control group received vehicle for 21 days.

Macamides exerted neuroprotective and anti-inflammatory effects, and significantly improved exercise endurance in rats by increasing the expression of AMPK and its downstream antioxidant target genes. Macamides mitigate ROS produced by the mitochondrial respiratory chain that accumulates in skeletal muscle, reversing fatigue and oxidative damage to cells. Based on theories about the mechanisms of physical fatigue, the accumulation of metabolites due to exercise can cause mental fatigue, and supplementation with macamide can protect the central nervous system from excitotoxicity.

Clinical evidence (very limited): A 2024 systematic review and meta-analysis of 21 studies (including animal and human data) confirmed maca's positive impact on physical performance and stamina, with large effect sizes observed for endurance, strength, and reduced lactic acid accumulation. This meta-analysis included animal studies, limiting its direct applicability to human supplementation with macamide-enriched extracts.

Summary of evidence strength: Anti-fatigue effects of macamides are supported by multiple animal and in vitro studies, with the proposed mechanism involving AMPK activation, mitochondrial ROS reduction, and anti-inflammatory pathways. Human evidence for isolated macamide fractions is absent; the body of evidence for whole maca on exercise performance remains modest.

7.4 Bone Health and Anti-Osteoporosis Effects

Preclinical evidence only:

Macamides are a unique class of non-polar, long-chain fatty acid N-benzylamides with fertility-enhancing, neuroprotective, neuro-modulatory, anti-fatigue, and anti-osteoporosis effects. Animal studies have suggested that red maca may help maintain bone mineral density, potentially relevant for postmenopausal osteoporosis. However, no human clinical data exist for this indication.

Summary of evidence strength: Anti-osteoporosis effects attributed partly to macamides are supported only by animal data. No clinical trials have investigated this outcome specifically for macamide-enriched preparations.

7.5 Antioxidant Activity

Macamides have shown antioxidant activity as one of their best-known properties and great potential as therapeutic agents; however, studies investigating this activity in humans are limited. Antioxidant effects have been observed in in vitro assays and animal models, including the reduction of exercise-induced oxidative stress, but translation to human clinical outcomes via macamide-specific supplementation has not been established.

7.6 Anticonvulsant / Epilepsy

A 2025 study examined synthetic macamides in epilepsy models. Epilepsy is a chronic neurological disorder that affects nearly 50 million people worldwide. Experimental evidence suggests that epileptic neurons are linked to the endocannabinoid system and that inhibition of the FAAH enzyme could have neuroprotective effects by increasing the levels of endogenous endocannabinoid anandamide. The use of macamides as therapeutic agents in neurological diseases has increased in recent years. This work remains in silico and in vivo (animal model) stages; no human clinical data exist for this application.

7.7 Mood, Energy, and Quality of Life

One randomized, double-blind, placebo-controlled study administered maca preparations to a large cohort: a total of 175 participants were given 3 g of either placebo, black, or red maca extract daily for 12 weeks. Primary outcomes were changes in sexual desire, mood, energy, health-related quality of life score (HRQL), and chronic mountain sickness (CMS) score, or glycaemia, blood pressure, and hemoglobin levels. Secondary outcomes were acceptability and safety, assessed using the Likert test and side effect self-recording. Consumption of spray-dried extracts of red and black maca resulted in improvement in mood, energy, and health status, and reduced CMS score. Since fatty acids and macamides were higher in spray-dried extracts of black maca than in red maca, differential macamide content may be relevant to the observed outcomes, though causation was not established for macamides specifically.

8. Body Systems and Health Areas Associated with Macamides

A total of 57 preclinical studies on maca were found reporting one or more effects, the most frequent being neuroprotective, anti-inflammatory, immunoregulatory, antioxidant, anti-fatigue, and fertility-related. Other effects less frequently reported include metabolic, gastrointestinal, cardioprotective, antihypertensive, photoprotective, anabolic, hepatoprotective, proangiogenic, antithrombotic, and antiallergic.

Summarizing the body systems associated with macamide research:

• Central Nervous System: Neuroprotection via CB1 receptor agonism and FAAH inhibition; potential in neurodegenerative and ischemic injury models; GPCRs modulation; cognitive function in scopolamine models.
• Endocannabinoid System: Direct FAAH inhibition, indirect elevation of anandamide levels; PPARγ activation.
• Reproductive System: Spermatogenesis, sperm motility, sexual desire — studied primarily via whole maca preparations in animal and limited human trials.
• Skeletal Muscle / Physical Performance: Anti-fatigue effects via AMPK pathway activation, mitochondrial ROS reduction, and anti-inflammatory action.
• Musculoskeletal System: Anti-osteoporosis effects in animal models.
• Immune System: Immunoregulation reported in preclinical studies.
• Cardiovascular System: Antihypertensive and antithrombotic effects noted in preclinical literature; in silico analysis showed macamides demonstrated greater affinity for the active site of renin.

9. Dosage Forms and Dosages Reported in Research

Maca is available commercially in several dosage forms including powder, liquid, tablets, and capsules.

The following dosages have been reported in specific studies:

• In a prolonged swimming mouse model, the macamides groups received commercial macamide products at 12 and 40 mg/kg by intragastric gavage for 21 days.
• In a human study on sperm parameters, gelatinized maca root was given at 1,500 or 3,000 mg/day to 9 healthy men over 4 months.
• In a randomized, double-blind, placebo-controlled study, 175 participants were given 3 g of either placebo, black, or red maca extract daily for 12 weeks.
• In FAAH inhibition assays, four macamides were tested at concentrations between 1 and 100 μM.
• Macamide concentrations from 1 to 100 μM were tested using FAAH and MAGL inhibitor assay methods.
• No adverse reactions were reported in an animal study with rats fed maca extract in doses up to 5 g/kg.

It must be noted that most human trials have used whole maca root powder or gelatinized extract standardized to total macamide content — not isolated macamide fractions. Human dosing data specific to macamide isolates is not available from the peer-reviewed literature to date.

10. Safety Considerations

10.1 General Safety Profile of Maca (Parent Source)

Maca is generally safe, with rare adverse effects, supported by preclinical studies revealing low toxicity and good human tolerance.

Maca has been reported to have a low degree of acute oral toxicity in animals and low cellular toxicity in vitro. No adverse reactions were reported in an animal study with rats fed maca extract in doses up to 5 g/kg.

There are no reports of adverse reactions after consuming Lepidium meyenii as food.

10.2 Macamide-Specific Tolerability

Macamides have been proposed as active drugs to treat some neurological disorders. Their excellent human tolerance and low toxicity along with neuroprotective, immune-enhancing, and antioxidant properties make them ideal for exploration as therapeutic agents. However, formal macamide-specific clinical safety studies have not been reported to the extent that a comprehensive toxicological profile for isolated macamides has been established.

10.3 Bioavailability of Individual Macamides

The administration of a macamide (benzyloctadecadienamide) showed greater inhibitory potency of soluble epoxide hydrolase (sEH) and better bioavailability than other macamides, as well as persistent antinociceptive effects for more than 6 hours. Differences in bioavailability across individual macamide structures are an active area of investigation.

10.4 Precautions Related to Glucosinolate Content

Patients with thyroid conditions should avoid maca because glucosinolates taken in excess and combined with a low-iodine diet can cause goiter. This concern applies to the glucosinolate content of maca preparations, not to macamides per se, but is relevant for maca-based products in which both classes of compounds are present.

10.5 Pregnancy and Lactation

Avoid use during pregnancy and lactation due to lack of safety and efficacy data.

10.6 Product Variability and Standardization

Thirty-five commercial maca products were surveyed for macamide composition and content by HPLC-UV/MS. Significant variations of macamide content were found in these products (69–2738 µg/g). This approximately 40-fold range of macamide content across commercial preparations is a major practical safety and efficacy concern, as consumers cannot assume a consistent pharmacologically active dose from labeled products. Maca root extracts purified to specific groups of bioactive compounds, including macamides, require further evaluation for possible risk to health. Individual USP-NF quality monographs for these articles are currently in development.

10.7 Research Gaps in Safety Science

The relationship between the structures and pharmacological effects of macamides has not been fully established. In addition, little is known regarding their biosynthetic pathways and the mechanisms underlying the biological activities. Systematic clinical toxicological data on macamide isolates — particularly pharmacokinetics, drug-drug interactions, and long-term safety at concentrated doses — are largely absent from the published literature as of the time of writing.

11. Current Research Frontiers and Knowledge Gaps

Macamides are a unique class of non-polar, long-chain fatty acid N-benzylamides with fertility-enhancing, neuroprotective, neuro-modulatory, anti-fatigue, and anti-osteoporosis effects. However, the relationship between the structures and pharmacological effects of macamides has not been established so far. In addition, little is known regarding their biosynthetic pathways and the mechanisms underlying the biological activities.

Macamide N-benzyl-hexadecanamide (NBH) was demonstrated to effectively improve mice's endurance ability by altering several fatigue-related biochemical markers. However, it is important to note that the mechanism underlying this effect remains unclear. Future experiments could utilize techniques such as transcriptomics or metabolomics to gain a more comprehensive understanding of the molecular pathways involved in macamide's anti-fatigue activity.

Research priorities for macamides include: formal pharmacokinetic studies in humans; dose-ranging clinical trials using macamide-standardized extracts; controlled trials to disentangle macamide effects from those of other maca constituents; and long-term safety evaluation for concentrated macamide preparations. The synthesis of macamide analogs is also an active area, as a synthetic macamide originally isolated from Lepidium meyenii has demonstrated inhibitory activity of FAAH.

References

• Analysis of macamides in samples of Maca (Lepidium meyenii) by HPLC-UV-MS/MS — PubMed
• Macamides present in the commercial maca products and the macamide biosynthesis affected by postharvest conditions — International Journal of Food Properties
• The macamide relieves fatigue by acting as inhibitor of inflammatory response in exercising mice — European Journal of Pharmacology (ScienceDirect)
• Neuroprotective activity of macamides on manganese-induced mitochondrial disruption in U-87 MG glioblastoma cells — PubMed
• Macamides: A review of structures, isolation, therapeutics and prospects — Food Research International (ScienceDirect)
• Effects of macamides on endurance capacity and anti-fatigue property in prolonged swimming mice — PubMed
• Exploring the chemical and pharmacological variability of Lepidium meyenii: a comprehensive review of the effects of maca — Frontiers in Pharmacology (PMC)
• Progress on the Chemical Constituents Derived from Glucosinolates in Maca (Lepidium meyenii) — PMC
• Lepidium meyenii (Maca): a plant from the highlands of Peru — from tradition to science — PubMed
• Ethnobiology and Ethnopharmacology of Lepidium meyenii (Maca), a Plant from the Peruvian Highlands — PMC
• Not All Maca Is Created Equal: A Review of Colors, Nutrition, Phytochemicals, and Clinical Uses — PMC
• Peruvian Maca: Two Scientific Names Lepidium meyenii Walpers and Lepidium peruvianum Chacon — Are They Phytochemically-Synonymous? — PMC
• Inhibition of Fatty Acid Amide Hydrolase (FAAH) by Macamides — PubMed
• The Macamide N-3-Methoxybenzyl-Linoleamide is a Time-Dependent Fatty Acid Amide Hydrolase (FAAH) Inhibitor — Molecular Neurobiology (Springer)
• Macamides and their synthetic analogs: Evaluation of in vitro FAAH inhibition — Bioorganic & Medicinal Chemistry (ScienceDirect)
• Macamides as Potential Therapeutic Agents in Neurological Disorders — Neurology International (PMC)
• Anticonvulsant Effects of Synthetic N-(3-Methoxybenzyl)oleamide and N-(3-Methoxybenzyl)linoleamide Macamides — Molecules (MDPI)
• Maca (L. meyenii) for improving sexual function: a systematic review — BMC Complementary Medicine and Therapies (PMC)
• A pilot investigation into the effect of maca supplementation on physical activity and sexual desire in sportsmen — Journal of Ethnopharmacology (ScienceDirect)
• Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled Study — PMC
• Comprehensive Profiling of Macamides and Fatty Acid Derivatives in Maca with Different Postharvest Drying Processes Using UPLC-QTOF-MS — ACS Omega
• Glucosinolate catabolism during postharvest drying determines the ratio of bioactive macamides to deaminated benzenoids in Lepidium meyenii (maca) root flour — Phytochemistry (ScienceDirect)
• The Efficient Synthesis and Anti-Fatigue Activity Evaluation of Macamides — Molecules (MDPI)
• Maca Uses, Benefits & Dosage — Drugs.com Natural Products Database