Gas e Hinchazón

Beta-sitosterol is a plant sterol found in saw palmetto and pumpkin seed oil that competitively inhibits 5α-reductase, reducing DHT conversion. An early double-blind RCT (Prager 2002, Journal of Alternative and Complementary Medicine, n=19 men with AGA) showed 60% of treated patients rated as 'improved' versus 11% for placebo at 5 months. It is the key active constituent underlying pumpkin seed oil's documented AGA efficacy.

Topical caffeine inhibits phosphodiesterase, raises cyclic AMP in follicular keratinocytes, and counteracts DHT-induced growth suppression, prolonging the anagen phase. A 2025 double-blind, placebo-controlled 24-week RCT (Celleno et al., PMC12359291) with a caffeine-containing shampoo showed significantly fewer hairs pulled (−2.8 vs +0.6, P<0.001) and improved phototrichogram parameters in male AGA versus placebo.

Curcumin downregulates androgen receptor expression in hair follicle cells and reduces scalp inflammation via NF-κB suppression, countering DHT-driven follicular miniaturization. It is a core ingredient of Nutrafol, evaluated in AGA clinical trials. The 2025 Frontiers in Nutrition systematic review (10.3389/fnut.2025.1719711) identifies curcumin among dietary supplements with evidence for AGA benefit.

EGCG, the major catechin of green tea, selectively inhibits 5α-reductase and stimulates dermal papilla cell proliferation and survival. PMC reviews (PMC11549889, PMC9963650) and a 2025 Frontiers in Nutrition systematic review confirm EGCG among phytochemicals with documented beneficial effects in AGA. In vitro and preclinical studies consistently support its DHT-reducing and follicle-promoting mechanisms.

The same 2015 Phytotherapy Research study by Shin HS et al. specifically modeled androgenic (male pattern) alopecia using DHT induction. Forsythiaside A outperformed finasteride in protecting hair follicles from DHT-induced damage in vitro and in vivo. This is the same scientific evidence as for Hair Loss above, specifically applicable to the androgen-dependent mechanism of male pattern hair loss.

Panax ginseng (red ginseng) ginsenosides inhibit 5α-reductase, stimulate dermal papilla cell proliferation, and improve scalp microcirculation. PMC reviews (PMC9963650, PMC11549889) cite red ginseng extract among phytochemicals with documented beneficial effects in AGA. A clinical study showed significant improvement in hair density with topical red ginseng application in AGA patients over 90–270 days.

Green tea (Camellia sinensis) polyphenols—primarily EGCG—inhibit 5α-reductase and stimulate dermal papilla cell proliferation relevant to AGA. Preclinical studies and multiple PMC systematic reviews (PMC9963650, PMC11549889) confirm hair growth-promoting effects, and green tea components appear in multiple evidence-based combination AGA supplement trials.

L-cystine is the disulfide form of cysteine essential for keratin biosynthesis and hair shaft structural integrity. A 2025 double-blind, placebo-controlled RCT (Piquero-Casals et al., Skin Appendage Disorders, n=80) with an oral supplement combining L-cystine, Serenoa repens, Cucurbita pepo, and Pygeum africanum showed significant hair density increases (+9.9 hairs/cm² at 3 months) and improved hair volume in AGA patients over 6 months.

Topical melatonin (0.1% solution) exhibits antioxidant and mild anti-androgenic properties. Five clinical studies (Fischer et al., Int J Trichology, 2012) showed positive effects on hair density and anagen phase in men and women with AGA. A 2025 network meta-analysis ranked topical melatonin as the highest-performing non-conventional AGA treatment after 5% minoxidil (SUCRA=61.9%).

Androgenetic alopecia (AGA) is explicitly listed in WebMD as a traditional use for oriental arborvitae, and multiple recent scientific studies have investigated P. orientalis for AGA-specific mechanisms. Studies have demonstrated activity against DHT-mediated follicle miniaturization pathways and UV-induced damage in AGA hair samples. Traditional Chinese medicine classics recognize the plant for hair darkening and regeneration.

Topical procyanidin B2 (from apple and grape polyphenol extract) promotes hair follicle cell proliferation via Wnt/β-catenin signaling and VEGF upregulation. Multiple Japanese RCTs (Takahashi 1998, Kamimura 2000/2002) demonstrated significant increases in terminal hair count versus placebo at 6 months. Topical procyanidin 0.7% was included in the 2025 network meta-analysis of male AGA trials as one of nine active comparators.

Pumpkin seed oil (Cucurbita pepo) contains beta-sitosterol and linoleic acid that inhibit 5α-reductase, reducing scalp DHT and IL-6-mediated inflammation. A landmark 24-week double-blind, placebo-controlled RCT (Cho 2014, PMC4017725, n=76 men with AGA) showed a 40% mean increase in hair count at 400 mg/day versus 10% for placebo (P<0.001). A 16-week RCT (PMC10648974, 2023) also confirmed significant improvements in hair density and anagen/telogen ratio.

Pygeum africanum (Prunus africana) bark extract contains phytosterols including beta-sitosterol with anti-androgenic and anti-inflammatory properties relevant to AGA. A 2025 double-blind, placebo-controlled RCT (Piquero-Casals et al., Skin Appendage Disorders, n=80, 6 months) testing an oral supplement combining Pygeum africanum, Serenoa repens, Cucurbita pepo, and L-cystine showed significant improvement in hair density (+9.9 hairs/cm² at 3 months) in AGA patients. Pygeum primarily features in combination AGA formulations.

Topical rosemary oil (Rosmarinus officinalis) enhances microcapillary perfusion and modulates prostaglandin E2 and leukotriene B4, prolonging the anagen phase. A randomized comparative trial (Panahi 2015, n=100) showed rosemary oil equaled 2% minoxidil in significant hair count increases at 6 months, with less scalp itching. A 2025 network meta-analysis confirmed topical rosemary as one of the best-evidenced non-conventional treatments for male AGA.

Saw palmetto (Serenoa repens) lipidosterolic extract inhibits both type I and II 5α-reductase, reducing DHT-driven follicular miniaturization in androgenetic alopecia (AGA). Multiple RCTs and a 2020 systematic review of 5 RCTs confirm improvements in hair density and count in men with AGA. Effects are smaller than finasteride but the tolerability profile is favorable.

An in vitro study demonstrated that L-threonate inhibits DHT-induced DKK1 (Dickkopf-1) expression in human hair dermal papilla cells. DKK1 is a key mediator of androgen-driven hair follicle miniaturization in androgenic alopecia. This is cell-culture evidence only, with no human clinical trials.

Tocotrienols are vitamin E isomers with potent antioxidant activity that reduce scalp lipid peroxidation associated with alopecia. A randomized, placebo-controlled trial (Beoy et al., 2010, PMC3819075; n=38) demonstrated a statistically significant 34.5% increase in hair count after 8 months of 100 mg/day mixed tocotrienols versus 0.1% decrease with placebo. The 2025 Frontiers in Nutrition systematic review cites this RCT for AGA.

Biotin (vitamin B7) is essential for keratin biosynthesis and widely used in AGA combination therapies. A 2024 PMC review (PMC11324195) documents its inclusion in compounded topical formulations with minoxidil, finasteride, and caffeine that promoted normal hair growth in male AGA. A 2024 systematic review (PubMed 39440586) identifies vitamin B deficiency as associated with increased AGA risk.

Vitamin D3 regulates hair follicle cycling via vitamin D receptor (VDR) signaling; VDR mutations cause alopecia. A 2024 systematic review (PubMed 39440586, 49 studies) identified vitamin D as one of four critical micronutrients whose deficiency is consistently associated with AGA risk and whose supplementation shows potential benefit for hair growth.

Zinc is a cofactor for 5α-reductase and enzymes involved in hair follicle cycling and keratin synthesis. A 2024 systematic review (PubMed 39440586, 49 studies) found zinc deficiency consistently associated with increased AGA risk, with supplementation showing potential benefit. A 2014 Journal of Drugs in Dermatology review identifies zinc among the best-evidenced supplemental treatments for AGA.

Horsetail (Equisetum arvense) has been used in European folk medicine as a hair-strengthening tonic due to its high silica content supporting keratin cross-linking. A 2018 placebo-controlled study (Pekmezci, n=120 AGA/TE subjects) using a multi-herb formula including Equisetum arvense leaf extract showed significantly reduced hair loss versus placebo. It is included in a 2025 registered RCT for AGA combination supplementation.

Stinging nettle (Urtica dioica) has centuries of use in European folk medicine and Ayurvedic traditions as a hair tonic to reduce loss and promote growth. In vitro studies show nettle root extract inhibits 5α-reductase and interferes with DHT-receptor binding. A 2018 placebo-controlled study (Pekmezci, n=120) using a multi-herb formula including Urtica dioica root extract showed significantly reduced hair loss in AGA subjects over 6 months.