Balsam: A Comprehensive Reference
1. Identity and Nomenclature
The term balsam, in the context of natural medicine and dietary supplementation, most commonly refers to two closely related aromatic resins derived from a single tree species: Myroxylon balsamum (L.) Harms (family Fabaceae / Leguminosae). The plant is the only species within the genus Myroxylon; however, there are two varieties — var. pereirae and var. balsamum — known respectively as Balsam of Peru and Balsam of Tolu. These two preparations, while derived from the same botanical source, are harvested differently and have somewhat distinct chemical profiles and traditional applications.
Balsam of Peru
Balsam of Peru, also known and marketed by many other names, is a balsam derived from Myroxylon balsamum var. pereirae; it is found in Central and South America. Its accepted scientific name is Myroxylon balsamum (L.) Harms var. pereirae (Royle) Harms. Common names include Balsam of Peru, Balsamo blanco, Baumier du Perou, Black balsam, Indian balsam, Peru balsam, Perubalsambaum, and Peruvian balsam. Synonyms include Myroxylon pereirae (Royle) Klotzsch, Myrospermum pereirae Royle (basionym), and Toluifera pereirae (Royle) Baill.
The name "balsam of Peru" is a misnomer. In the early period of the Spanish conquest of Central and South America, the balsam was collected in Central America and shipped to Callao (the port of Lima) in Peru, then shipped onward to Europe. It acquired the name "Peru" because it was shipped via there. Actually, the balsam of Peru — which belongs to the family Fabaceae, nowhere close to the family of the Old World balsam (Burseraceae) — originally came from the part of Central America known as Salvador, or the "balsam coast," so the name is at least misleading.
Balsam of Tolu
Tolu balsam's accepted scientific name is Myroxylon balsamum (L.) Harms var. balsamum. Common names include arbol de Tolu, balsam of Tolu, balsamum tolutanum, estoraque, opobalsam, resin tolu, resina tolutana, Thomas balsam, and Tolu balsam tree. It got its name because it was shipped to Europe from Tolú, Colombia. In 1753, Linnaeus described the type specimen as Toluifera balsamum, naming it in relation to the place of collection.
Natural Source and Tree Characteristics
The species Myroxylon balsamum is a tall tree (15 to 23 m high) native to the high plains and mountains of Central and South America. The plant bears evergreen pinnate leaves and racemes of white flowers. The hardwood tree contains oil that is naturally resistant to insects and has a characteristic scent. These trees are primarily found in Central America, with El Salvador being the main producer.
Extraction and Common Preparations
The two balsams are obtained by different extraction methods. Peru balsam is an oily sap obtained by removing the bark of the Myroxylon balsamum tree and scorching the exposed wood. Tolu balsam, by contrast, is obtained from the same tree by making a V-shaped cut through the bark and underlying wood.
Tolu balsam is a pathological resin, formed in trunk tissues as a result of injuries. It is collected by making V-shaped incisions in the bark and sapwood, with calabash cups placed to receive the flow of balsam.
Common forms and preparations encountered in commerce and clinical use include:
- Crude resin: The raw dark-brown or amber aromatic fluid obtained directly by the extraction processes above.
- Topical ointments and creams: Peru balsam has been used topically in 5% to 20% formulations for wounds and burns.
- Pharmaceutical syrups and cough preparations: Tolu balsam has been used for centuries as a fragrance in perfumes and as a flavoring in candies and chewing gums. Today it remains in use in pharmaceutical preparations in the form of a syrup as an expectorant and as a fragrant vehicle for other compounds.
- Suppositories: Peru balsam has been used in suppositories for hemorrhoids.
- Rectified/distilled extracts: The fragrance industry banned the use of crude balsam of Peru in perfumes in 1982 through the International Fragrance Association (IFRA); however, refined extracts and distillates of the resin are still permitted and widely used in scented products.
2. Historical and Traditional Use
Indigenous and Pre-Columbian Use in the Americas
Central and South American natives used the material to stop bleeding and promote wound healing. They also used the material as a diuretic and to expel worms. Indigenous communities in Central and South America applied the resin to cuts, burns, and ulcerated skin to reduce pain, control infection, and encourage healing.
Colonial-Era European Introduction and Spread
The export of balsam of Peru to Europe was first documented in the seventeenth century in the German pharmacopoeia. Jerusalem Balsam, a related herbal formulation, came into use in the seventeenth century. It was widely used in Europe since the nineteenth century as a remedy possessing antibacterial, antifungal, and anti-inflammatory activities.
Connections between China and the new Spanish colonies in America are known for the exchange of silver for silks and porcelains. That medicinal drugs and medicinal knowledge also crossed the Pacific Ocean is hardly known or discussed. The medicinal qualities of balsam, especially against skin diseases and sores, were already known in China during Tang times. It was only with the advent of the Jesuits that balsam from the New World — that is, from the new Spanish colonies in America — was introduced as the balsam of Peru.
Traditional Pharmacopeial History
Balsam of Tolu was included in the U.S. Pharmacopeia in 1820, reflecting its early codification in official medicine. In 1841, Henri Étienne Sainte-Claire Deville isolated toluene by the dry distillation of tolu balsam — a landmark in organic chemistry demonstrating the compound's importance beyond medicine.
Traditional Therapeutic Indications (by Tradition)
Across cultures and time periods, balsam has been applied for the following conditions, as recorded in historical and ethnobotanical literature:
- Wound and skin care: Peru Balsam has historically been used as a topical ointment for various skin conditions such as scabies, poorly healing wounds, eczema, and haemorrhoids.
- Respiratory complaints: Modern herbalism values Tolu balsam as a feeble expectorant used in cough mixtures and as an inhalant for catarrh and bronchitis. It is also used as a cough suppressant and respiratory aid in cough lozenges and syrups, for sore throats, and as a vapour inhalant for respiratory ailments.
- Dentistry: Peru balsam has been used in the treatment of dry socket in dentistry, topically as a treatment for wounds and ulcers, and in suppositories for hemorrhoids.
- Antiseptic and antimicrobial applications: Tolu balsam has mild antiseptic properties and is used in the treatment of bedsores, cracked nipples, and minor skin cuts.
3. Chemical Constituents and Active Compounds
Balsam of Peru
The balsam contains 50% to 65% of a volatile oil called cinnamein, along with about 25% resin. The volatile oil primarily contains benzyl cinnamate and other benzoic and cinnamic acid esters, with small amounts of benzyl alcohol and related compounds. Balsam of Peru contains 25 or so different substances, including cinnamein, cinnamic acid, cinnamyl cinnamate, benzyl benzoate, benzoic acid, and vanillin. It also contains cinnamyl alcohol, cinnamaldehyde, farnesol, and nerolidol.
About 60 to 70 percent of the resin is cinnamein — a mixture of cinnamic acid, benzyl benzoate, benzoic acid, and vanillin. The remaining 30 to 40 percent consists of resins whose exact composition is still not fully characterized.
A 2020 molecular profiling study using gas chromatography/mass spectrometry on both a historical and a modern sample of Peru Balsam provided further chemical detail: Both Peru Balsam specimens investigated had similar compositions, showing the stability of the substance. Components identified are effective against scabies, exhibit antimicrobial activity, and aid skin penetration. The study identified a combination of α-terpineol and nerolidol demonstrating potent antimicrobial activity and markedly inhibiting biofilm development, particularly against Gram-positive bacterial strains.
Balsam of Tolu
Tolu balsam contains between 1.5 and 3% essential oil and also resin (80%) with benzoic acid, benzyl cinnamate, benzyl benzoate, and cinnamic acid. Modern pharmacopoeias now mainly treat Tolu balsam as a flavoring and fragrance ingredient, yet interest in its medicinal potential persists. It contains aromatic acids and esters that may provide mild antiseptic, expectorant, and skin-protective actions.
Key Active Compounds and Proposed Mechanisms
Benzyl benzoate is a critical bioactive constituent of both balsams. Benzyl benzoate is an organic compound used as a medication and insect repellent; as a medication it is used to treat scabies and lice. How it works against scabies is unclear. Benzyl benzoate was first studied medically in 1918 and is on the World Health Organization's List of Essential Medicines.
Benzoic acid has been identified as exerting antimicrobial action: Benzoic acid is a cytostatic and is commonly used as a preservative. It exerts antimicrobial activity by the suppression of macro-autophagy.
Cinnamic acid: Cinnamic acid has been shown to be effective across a wide range of bacteria and fungi.
CD1a-mediated immunological mechanism: Research has elucidated part of the immunological mechanism behind balsam's allergenicity. Using CD1a autoreactive human αβ T cell clones to screen clinically important allergens, researchers identified responses to balsam of Peru, a tree oil widely used in cosmetics and toothpaste. Additional purification identified benzyl benzoate and benzyl cinnamate as the antigenic compounds within balsam of Peru.
4. Scientific Evidence by Area of Use
4.1 Scabies Treatment
Balsam of Peru is used in the treatment of scabies in a manner similar to sulfur-containing formulations. The antiparasitic effect is attributed to its content of thymol and benzyl benzoate. Benzyl benzoate, isolated from balsam, has an extensive clinical track record as a scabicide. Benzyl benzoate remains one of the most commonly prescribed agents for scabies in many parts of the world and compares favorably with other topical agents and oral ivermectin. It is not available in the US or Canada. The 25% emulsion is applied below the neck with three applications during a 24-hour period; in young adults or children, the concentration can be reduced to 12.5%.
A clinical consensus from Turkey identifies balsam of Peru, along with permethrin, sulfur mixtures, and benzyl benzoate, as first-line topical therapy for classic scabies.
Evidence strength: Moderate for its constituent benzyl benzoate as an isolated scabicide; limited for crude balsam of Peru as a standalone preparation, largely based on older clinical reports and historical usage. Peru balsam has been used in the treatment of dry socket in dentistry, topically as a treatment for wounds and ulcers, and in suppositories for hemorrhoids; however, there are only older, small case studies to support this use.
4.2 Wound Healing and Dermatological Applications
Clinical evidence is most robust for topical wound care, but even here it is modest by modern standards. Small studies and case series suggest that ointments combining Peru balsam with carrier oils and enzymes can support healing of partial-thickness wounds, donor sites for skin grafts, radiation-induced skin damage, and some chronic ulcers.
Various ointments using blends such as castor oil, Peru balsam, and proteolytic enzymes have shown benefits for partial-thickness wounds, donor graft sites, or radiation-damaged skin in small clinical studies.
At the molecular level, Peru balsam's antimicrobial and wound-healing effects are supported by its chemical constituents such as benzyl benzoate and cinnamic acid derivatives, which contribute to its use as a mild antiseptic, promoting tissue repair by enhancing local circulation and inhibiting microbial growth.
Evidence strength: Weak to preliminary for wound healing in humans. Available studies are small, uncontrolled, or of older vintage and do not meet current standards for clinical evidence. Historical and pharmacological data indicate its efficacy in treating superficial skin conditions, though modern clinical evidence remains limited to small-scale studies.
4.3 Dental Applications (Dry Socket / Postextraction Alveolitis)
In medicine, balsam of Peru has been used topically for wound care, burns, frostbite, and poorly healing ulcers, typically in formulations of 5 to 20% concentration. It has also been used in suppositories for hemorrhoids and in dentistry to treat dry socket, the painful condition that sometimes follows a tooth extraction.
Evidence strength: Limited to older case reports and small studies. No recent, well-controlled clinical trials establish efficacy specifically in dental applications.
4.4 Respiratory and Expectorant Uses
Tolu balsam has an antimicrobial and expectorant effect, and is used for catarrh of the upper respiratory tract. However, Tolu balsam is purported to have expectorant properties and is a component of compound benzoin tincture; however, there are no animal or clinical studies to support its use for any condition. Tolu balsam is best known for its fragrance and use as flavoring in pharmaceutical products, although it also has mild antiseptic and expectorant properties. There are no clinical data to support its use in any condition.
Evidence strength: No clinical trial evidence for expectorant or respiratory effects. Use in cough preparations is based entirely on tradition and pharmacopeial convention, not controlled human studies.
4.5 Antimicrobial Activity
Components of Peru Balsam identified by molecular profiling are effective against scabies, exhibit antimicrobial activity, and aid skin penetration, with these properties consistent with historical uses. The study specifically found that the combination of α-terpineol and nerolidol demonstrated potent antimicrobial activity and markedly inhibited biofilm development, particularly against Gram-positive bacterial strains.
Evidence strength: Preclinical (in vitro) only. No human clinical trials have specifically evaluated crude balsam preparations for infectious disease endpoints.
4.6 Contact Allergy Diagnosis (Patch Testing)
One of the best-documented clinical roles of balsam of Peru is not therapeutic but diagnostic. Balsam of Peru (Myroxylon pereirae, INCI) has been used as a screening allergen for years. While the balsam as such is not used in cosmetic products in Europe, extracts and distillates are. With a prevalence of sensitization between 3.9% and 8.0% in consecutively-tested patients in Europe and strong associations with other fragrance allergens, balsam of Peru is a "traditional" but still common allergen, although the composition and role of individual ingredients as sensitizing agents has not yet been fully explained.
Based on published results, balsam of Peru appears to be still worth testing alongside fragrance mix I in baseline patch test series, because it allows detection of a remarkable number of fragrance allergies — often clinically relevant — that would otherwise be missed.
A 2021 study of 11,978 patients in the IVDK (Information Network of Departments of Dermatology) found: Positive reactions to both balsam of Peru and fragrance mix I were observed in 119 subjects (1.0%), 310 (2.6%) reacted to balsam of Peru only, and 304 (2.5%) to fragrance mix I only. Single sensitizations were clinically relevant in 75.2% of cases for balsam of Peru (62.9% current, 12.3% past) and 76.3% for fragrance mix I.
Evidence strength: Strong. The role of balsam of Peru as a diagnostic patch test allergen for fragrance allergy screening is well established in dermatological literature, supported by large multicenter datasets.
5. Body Systems and Health Areas
Integumentary System (Skin)
Balsam of Peru is primarily associated with skin applications, both therapeutic and allergic. Its traditional topical roles include wound healing, antisepsis, treatment of scabies, eczema, hemorrhoids, pressure sores, and diaper rash. Conversely, its major clinical relevance in modern dermatology is as a potent fragrance allergen and patch test marker.
Respiratory System
Tolu balsam has the stronger association with respiratory health in historical and pharmacopeial tradition. Balsam of Tolu is used as an expectorant, stimulant, and antiseptic; it is an ingredient of cough mixtures and compound benzoin tincture, and is also used as a pleasant flavoring agent in medicinal syrups, confectionery, chewing gums, and perfumery.
Oral/Dental Health
Peru balsam has a documented, though older and poorly evidenced, history in dentistry for dry socket management and as a component of dental impression materials.
Immune System (Allergic Response)
Balsam of Peru is a significant sensitizer with a T-cell–mediated immunological mechanism involving CD1a antigen presentation. Research identified a human T cell response to balsam of Peru as a tree oil-derived contact allergen. Larger-scale screens defined the general chemical requirements for a T cell response to oily substances and discovered additional contact allergens presented by CD1a, including farnesol.
6. Dosage Forms and Reported Dosages
Dosage information is sparse and derives primarily from historical and pharmacopeial sources rather than modern clinical trials.
- Topical formulations (Peru balsam): Peru balsam has been used topically in 5% to 20% formulations for wounds and burns.
- Oral/internal use (Peru balsam): The material is not used internally.
- Tolu balsam — oral dose for respiratory conditions: Tolu balsam is used for catarrh of the upper respiratory tract; the average daily dose is 0.6 g and is usually taken in the form of cough syrups and cough drops. There is no recent clinical evidence to support specific dosing; a traditional dosage for colds has been 0.6 g daily.
- Benzyl benzoate (isolated constituent) for scabies: The 25% emulsion is applied below the neck with three applications during a 24-hour period. In young adults or children, the concentration can be reduced to 12.5%.
- Balsam of Peru for scabies: After bathing, the medication is applied to the whole body once a day for 2–3 consecutive days, while contact with the eyes should be avoided.
7. Safety Considerations and Interactions
Contact Allergy (Allergic Contact Dermatitis)
Balsam of Peru is a botanically-derived compound with reactions reported to be positive in up to 4% to 8% among individuals with suspected ACD. Balsam of Peru is an aromatic fluid that comes from the bark of the Myroxylon balsamum tree. Key ingredients including benzyl cinnamate, benzyl benzoate, benzoic acid, vanillin, and nerolidol can be found in three groups of products: fragrance in perfumes and toiletries, flavorings in foods and drinks, and medicaments.
The use of its constituents is widespread and found in cosmetics as well as foods, including ketchup. Cross-reactivity with naturally occurring sources of similar chemicals has been reported with orange peel, clove, and tomatoes.
Systemic Contact Dermatitis from Dietary Exposure
Systemic contact dermatitis (SCD) is a specific type of allergy triggered by food. SCD traditionally refers to a skin condition where an individual who is cutaneously sensitized to an allergen subsequently reacts to that same allergen or a cross-reacting allergen via a different route, such as through consumption of foods containing the allergen.
A double-blind, placebo-controlled oral challenge study involving 221 patients with various types of dermatitis provided important evidence: 210 patients completed the study, and 45 of them experienced a flare of their symptoms after challenge with balsam of Peru but not after placebo. Fifteen patients reacted to the placebo, and 5 reacted to both balsam and placebo.
In a retrospective U.S. study (Salam and Fowler, 2001): It was concluded that it seems possible that ingested balsam of Peru and related spices cause systemic allergic reactions in patients with delayed contact allergy to balsam of Peru. Of 45 patients allergic to balsam of Peru and/or fragrance mix I in whom dietary avoidance was recommended, 21 (47%) reported complete or significant improvement primarily related to dietary modification. Nine of 45 did not follow the recommended diet, and of these, only one (11%) had significant improvement. The food items most commonly mentioned as causes of flare-up of dermatitis were tomatoes, citrus, spices, cola or soda, chocolate, chili, cinnamon, beer or wine, and vinegar.
Some patients with dermatitis, especially those with forms suggestive of systemic allergic dermatitis (vesicular hand dermatitis, symmetrical dermatitis of the hands or feet, anogenital dermatitis, symmetrical dermatitis in large skin folds), may benefit from a diet that restricts foods containing balsams and certain spices such as cinnamon, cloves, and vanilla. Especially patients with positive patch test reactions to balsam of Peru — but also some patients who do not react to balsam of Peru but react to fragrance mix I — may benefit.
Immediate-Type (IgE-like) Hypersensitivity
Balsam of Peru is an aromatic liquid derived from the Myroxylon balsamum tree used in cosmetics, foods, beverages, and medicinal products. It contains cinnamic acid, cinnamyl cinnamate, benzyl benzoate, benzoic acid, and vanilla, as well as essential oils similar to those found in citrus fruit peel. It most commonly causes a contact dermatitis; highly allergic individuals may suffer adverse reactions after consuming foods containing balsam of Peru, including soreness of the tongue and mouth.
Regulatory Status and Restrictions
In the food industry, the U.S. FDA lists balsam of Peru as an approved food additive where it functions as a flavoring agent. On ingredient labels it may appear under several names: Myroxylon pereirae oleoresin, Peruvian balsam, or simply balsam Peru. The fragrance industry banned the use of crude balsam of Peru in perfumes back in 1982 through the International Fragrance Association (IFRA). However, refined extracts and distillates of the resin are still permitted and widely used in scented products including lotions, shampoos, soaps, and cosmetics. The IFRA additionally recommends not using crude Peru balsam in any finished product application.
Safety in Specific Populations
Use of benzyl benzoate — an active constituent of balsam — can be complicated by allergic contact dermatitis, and it should not be used during pregnancy, in lactating women, in infants, or in children younger than 2 years because of the risk for neurotoxicity. It should be noted that balsam of Peru may cause contact dermatitis.
For tolu balsam specifically: Contraindications have not yet been determined. Information regarding safety and efficacy in pregnancy and lactation is lacking. Allergic reactions to tolu balsam have been reported.
Fragrance Allergen Identification
An important feature of balsam allergy is its role as a proxy marker: Balsam of Peru is used in dermatological patch testing not to diagnose allergy to itself, but as a screening marker for fragrance allergy in general. A positive reaction to Peru balsam on patch test correlates with sensitivity to dozens of chemically unrelated fragrance compounds — cinnamates, benzoates, eugenol, farnesol, isoeugenol — because the balsam naturally contains trace amounts of so many common allergens at once. It remains in the European baseline patch test series to this day, functioning as a diagnostic shortcut rather than a single allergen identifier.
Several ingredients of Peru balsam are also known allergens, and the overlapping chemical compounds are part of what makes balsam of Peru so problematic for people with sensitivities: many of the same chemicals appear naturally in spices, citrus peels, and flavorings.
Drug and Product Interactions
No interactions between tolu balsam and other medications have been identified in the available literature. For balsam of Peru, the primary concern for cross-reactivity is with fragrance-containing products and foods. Implicated foods include spices, citrus fruit peel, baked goods, aperitifs, benzoic acid, and related preservatives. Both resins share many constituents and are often grouped together under fragrance and flavor regulations. In practice, this means that a sensitivity to one often implies a sensitivity to the other.
8. Summary of Evidence Strength
- Fragrance allergy patch test marker: Strong clinical evidence — well established in dermatological literature by large multicenter datasets and systematic reviews.
- Scabies treatment (via benzyl benzoate constituent): Moderate clinical evidence for benzyl benzoate as an isolated preparation; limited evidence for crude balsam as a preparation.
- Wound healing (topical): Weak clinical evidence — based on small case series and older uncontrolled studies.
- Systemic contact dermatitis and dietary intervention: Moderate clinical evidence from prospective challenge and retrospective diet studies, though study populations are small.
- Expectorant / respiratory uses (Tolu balsam): No clinical trial evidence — relies entirely on tradition and pharmacopeial convention.
- Antimicrobial activity: Preclinical (in vitro) evidence only — no controlled human trials.
- Dental (dry socket) applications: Weak, older clinical evidence only.
References
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