The Science Behind Our Hair Growth Oils at Kemetri Afro Infusions.

Abstract

Botanical oils and plant extracts are widely used for hair loss and hair health, especially among people seeking “clean” or culturally rooted alternatives to conventional drugs such as minoxidil and finasteride. In the last five years, a growing body of preclinical and clinical research has examined the effects of specific botanicals on the hair cycle, scalp environment, and signs of alopecia. This narrative review summarizes recent evidence (2020–2025) on several widely used ingredients in hair growth oils and masks, including henna (Lawsonia inermis), amla (Phyllanthus emblica), fenugreek (Trigonella foenum-graecum), ginseng (Panax ginseng), aloe vera (Aloe barbadensis), capsaicin-containing peppers (Capsicum spp.), and chebe mixtures (typically Croton zambesicus–based), along with other botanicals such as rosemary and pumpkin seed oil. Evidence for amla, ginseng, rosemary, and pumpkin seed oil now includes controlled human trials showing improvements in hair density or hair counts, while fenugreek, aloe vera, and capsaicin have emerging but still limited clinical data. Henna and chebe are supported primarily by animal data (henna) or anecdotal/cosmetic effects on breakage (chebe). Overall, plant-based formulations can support scalp health, reduce shedding, and in some cases increase hair density, but most studies are small, short term, and heterogeneous in formulation. More rigorous, standardized clinical trials—especially in tightly-curated oil blends—are needed, particularly in Afro-textured hair populations that use these products most.

Keywords: alopecia, hair growth, botanical oils, amla, ginseng, fenugreek, rosemary oil

Introduction

Alopecia, particularly androgenetic alopecia and telogen effluvium, is a common condition with substantial psychosocial impact. Conventional therapies such as topical minoxidil and oral finasteride can improve hair density but are limited by delayed onset of action, partial response, and potential adverse effects, motivating interest in complementary and plant-based approaches.(MDPI)

Recent mechanistic reviews emphasize that successful hair-growth interventions often act by (a) prolonging the anagen (growth) phase, (b) shortening telogen, (c) modulating androgen pathways (e.g., 5-α-reductase), (d) improving perifollicular microcirculation, or (e) reducing inflammation and oxidative stress around the follicle.(MDPI) Plant extracts rich in polyphenols, saponins, and lipids can target several of these pathways simultaneously, which explains the intense interest in botanical hair oils in both research and consumer markets.(PMC)

This review focuses on recent (2020–2025) data concerning henna, amla, fenugreek, ginseng, aloe vera, capsaicin-containing peppers, chebe mixtures, and selected additional botanicals frequently used in hair growth oils.

Methods

This is a narrative (not systematic) review. Electronic searches of PubMed, ScienceDirect, and Google Scholar were conducted for 2020–2025 using combinations of the terms hair loss, alopecia, hair growth, oil, topical, henna, Lawsonia inermis, Phyllanthus emblica, amla, fenugreek, Trigonella foenum-graecum, Panax ginseng, aloe vera, Capsicum, capsaicin, chebe, Croton zambesicus, pumpkin seed oil, and rosemary oil. Additional recent review articles and reference lists were used to identify primary studies. Preference was given to peer-reviewed in vitro, animal, and human clinical studies; cosmetology articles and industry white papers were used only to contextualize traditional or marketing claims when no primary data were available.(PMC)

Henna (Lawsonia inermis)

Henna is traditionally used as a dye and medicinal plant with antimicrobial, wound-healing, and antioxidant properties. Recent reviews summarized its broad pharmacological activity but only limited direct hair-growth data.(PMC)

A 2024 animal study evaluated ethanolic extracts of Lawsonia inermis flowers in a testosterone-induced alopecia mouse model. Topical application of henna flower extract (200–400 mg/kg, with or without olive oil) over 12 weeks significantly reduced alopecia index scores compared with untreated controls and showed efficacy comparable to 5% minoxidil in reducing bald area.(ResearchGate) This suggests henna extracts can counteract androgen-driven miniaturization in vivo, at least in rodents.

Another recent study focused on henna’s effects as a hair dye, showing that henna treatments altered surface morphology but preserved or improved some structural parameters of hair shafts compared with synthetic dyes, supporting a role as a relatively hair-friendly coloring option rather than a direct growth stimulant.(International Journal of Morphology)

Summary: Henna has plausible antioxidant and anti-androgenic activity and one recent positive mouse study, but no modern controlled human trials specifically assessing hair regrowth. At present, its evidence base for hair growth is preclinical rather than clinical.

Amla (Phyllanthus emblica)

Amla has a long history as a hair tonic in traditional systems of medicine.(Frontiers)

A triple-blind randomized controlled trial in 60 women with female androgenetic alopecia tested an oral amla syrup (10 mL three times daily for 12 weeks) versus placebo. The amla group showed a significant increase in the anagen-to-telogen ratio and higher physician and patient satisfaction, with minimal side effects.(ScienceDirect)

Another recent clinical study evaluated an amla-containing food supplement (“Vedistry Amla +” tablets) as an adjunct for healthy hair. Participants experienced reduced hair fall and improvements in texture, shine, and volume over several weeks of supplementation, with good tolerability.(ResearchGate) Although not targeted specifically to diagnosed alopecia, these data support amla’s role in overall hair health.

From a delivery-science perspective, a 2022 formulation study loaded Phyllanthus emblica extract into “transfersomes” (deformable vesicles) designed to target hair follicles. The system improved follicular accumulation of amla actives in ex vivo human skin, suggesting a promising vehicle for topical hair applications.(J-STAGE)

Summary: Amla currently has one well-designed RCT in FAGA and supportive formulation studies, making it one of the better-supported traditional botanicals for systemic or topical hair support.

Fenugreek (Trigonella foenum-graecum)

Fenugreek seeds contain proteins, nicotinic acid, saponins, and flavonoids with anti-inflammatory and antioxidant properties. A 2024 review on fenugreek’s “multifaceted potential” summarizes several clinical studies, including a double-blind trial of a fenugreek-based herbal gel in patients with trichoptilosis (split ends) that reduced hair loss and shaft damage over two months.(PMC)

A broader pharmacologic review of plant-based treatments for hair loss notes that fenugreek extracts may modulate inflammatory cytokines (e.g., IL-6, TNF-α) and support a healthier scalp environment, but emphasizes that clinical data are still limited and often bundled with other actives.(PMC)

Consumer-oriented summaries drawing on these studies report improvements in hair density and reduced shedding with fenugreek-containing supplements or topicals, but sample sizes are small and formulations heterogeneous.(Verywell Health)

Summary: Fenugreek shows promising mechanistic and small-trial evidence for reducing breakage and shedding and improving hair quality; however, robust, fenugreek-only RCTs in alopecia are still lacking.

Ginseng (Panax ginseng)

Ginseng—especially red ginseng—has some of the strongest mechanistic support among plant extracts used for hair growth.

A 2021 study by Truong and Jeong demonstrated that red ginseng extract increased viability and reduced apoptosis in human dermal papilla cells in vitro and promoted telogen-to-anagen transition, larger follicle bulbs, and thicker skin in C57BL/6 mice. These effects were associated with upregulation of β-catenin, cyclins, and growth factors such as IGF-1 and VEGF.(PubMed)

Red ginseng oil has also been shown to promote hair growth and protect skin in mouse models, likely via antioxidant effects and modulation of 5-α-reductase activity.(ScienceDirect) A 2025 study using an organ culture model of human hair follicles reported that red ginseng extract and selected ginsenosides reduced oxidative damage to follicular keratinocytes, supporting its use as a protective and reparative ingredient in hair formulations.(Annals of Dermatology)

A 2024 review on “ginseng and ginseng byproducts for skincare and skin health” highlights red ginseng’s capacity to increase hair follicle density and size in patients with androgenetic alopecia in earlier clinical work, and argues for its inclusion in cosmeceutical hair products.(ScienceDirect)

Summary: Ginseng has strong preclinical and encouraging early clinical data, particularly in red ginseng extract and oil. Mechanisms include pro-anagen signaling (Wnt/β-catenin), anti-oxidative effects, and potential anti-androgenic activity.

Aloe Vera (Aloe barbadensis Miller)

Aloe vera gel is widely used in scalp and hair care for its soothing, moisturizing, and antimicrobial properties. A 2025 qualitative review analyzed 30 studies (2016–2025) and concluded that aloe vera has potential to reduce hair loss, promote hair growth, and improve scalp health, especially when combined with other botanicals such as candlenut and lime. However, the authors noted a lack of large, high-quality human RCTs focused solely on hair outcomes.(ResearchGate)

A 2024 review of aloe vera in cosmetology describes its moisturizing, anti-inflammatory, and antioxidant effects, which may support the scalp environment and indirectly benefit hair growth.(ScienceDirect) In a broader review of natural alopecia treatments, aloe-containing formulations (often combined with other actives like Withania somnifera) accelerated hair growth initiation in animal models compared with vehicle controls.(Karger Publishers)

Summary: Aloe vera is well supported as a scalp-soothing, moisturizing, and antifungal co-ingredient, with suggestive but not yet definitive evidence for direct hair growth promotion.

Capsaicin-Containing Peppers (Capsicum spp.)

Capsaicin—the pungent compound in chili peppers—activates TRPV1 receptors on sensory neurons. TRPV1 stimulation can increase insulin-like growth factor-1 (IGF-1), a key growth factor for hair follicles.(Frontiers)

Older work showed that combined oral capsaicin and isoflavone increased IGF-1 and promoted hair growth in both mice and humans with alopecia. More recent reviews confirm this mechanism and revisit capsaicin as a potential therapeutic tool.(PubMed)

A 2025 clinical study examining non-pharmacologic approaches to hair health reported that a capsaicin-containing preparation increased vellus and non-cosmetic hair growth more than a clobetasol comparator in certain scalp areas, although details of formulation and population were limited.(ScienceDirect)

At the same time, TRPV1 overactivation can inhibit hair shaft elongation in vitro, highlighting the importance of dose and formulation.(ScienceDirect)

Summary: Capsaicin has plausible, IGF-1–mediated hair-growth mechanisms and some supportive human data, but its narrow therapeutic window and irritant potential mean it must be used carefully in topical oils.

Chebe (Croton zambesicus–Based Mixtures)

“Chebe powder” is a traditional mixture used by women in Chad and neighboring regions. Commercial analyses show that chebe products are typically blends of Croton zambesicus seeds (lavender croton) with cloves, cherry kernels, aromatic resins, and oils.(Elsie Organics)

Most modern claims about chebe’s hair growth benefits come from anecdotal reports, case studies from brands, and blogs describing reduced breakage, length retention, and increased thickness.(Chebeauty) These sources emphasize chebe’s ability to coat and lubricate hair shafts, retain moisture, and reduce mechanical damage—factors that are especially important for length retention in tightly coiled Afro-textured hair.

However, dermatologists note that there are no high-quality clinical trials directly testing chebe in alopecia, and that its main action is likely mechanical (reducing breakage) rather than biologically stimulating follicles.(Allure)

Summary: Chebe is best understood as a protective, length-retention treatment, not yet as an evidence-based follicle stimulant. It can still be valuable in a hair-growth routine by helping preserve the strands that do grow.

Other Botanicals in Hair Growth Oils

Rosemary (Rosmarinus officinalis)

Rosemary essential oil is one of the most studied hair-growth botanicals. A landmark 2015 trial found rosemary oil as effective as 2% minoxidil for androgenetic alopecia over six months, with less scalp itching; recent reviews continue to highlight this result.(Pharmacist.com)

A 2025 Cureus clinical trial of a proprietary rosemary-based blend (“Rosmagain™”) in 120 participants reported significant improvements in hair count, hair shaft diameter, and scalp health compared with placebo, reinforcing rosemary’s role as a core plant active for hair regrowth.(PubMed)

Pumpkin Seed Oil (Cucurbita pepo)

Pumpkin seed oil is rich in phytosterols that may inhibit 5-α-reductase. A randomized double-blind trial (originally published in 2014 but frequently cited in recent hair-loss reviews) found that men with androgenetic alopecia taking 400 mg/day pumpkin seed oil for 24 weeks achieved about 40% increased hair counts versus 10% in the placebo group.(Healthline) Recent derm and integrative-medicine commentaries continue to cite this study as evidence for oral pumpkin seed oil in male pattern hair loss.(hims)

Multi-Herb Formulations

Several newer trials have evaluated multi-ingredient supplements containing combinations of amla, fenugreek, ginseng, pumpkin seed oil, and micronutrients. These formulations generally show improvements in hair density, shedding, and patient satisfaction versus placebo over 3–6 months, but the contribution of any single herb cannot be isolated.(PMC)

Safety Considerations

Overall, botanicals discussed in this review appear well tolerated when used in cosmetic concentrations, but specific risks exist:

• Essential oils (rosemary, peppermint, tea tree) can cause irritant or allergic contact dermatitis; patch testing and proper dilution in carrier oils are important.(PMC)

• Capsaicin can cause burning, erythema, and paradoxical telogen effluvium if overused.(Frontiers)

• Henna is generally safe in pure form but “black henna” adulterated with para-phenylenediamine (PPD) can cause severe allergic reactions; only PPD-free products should be used.(PMC)

• Oral supplements (amla, fenugreek, pumpkin seed oil, ginseng) may interact with medications (e.g., anticoagulants, hypoglycemics); medical supervision is advisable for long-term or high-dose use.(PMC)

Discussion

Across 2020–2025, the evidence for botanical hair growth ingredients has become more nuanced. Ingredients such as amla, red ginseng, rosemary oil, and pumpkin seed oil now have at least one controlled clinical trial showing beneficial effects on hair growth parameters.(ScienceDirect) Others—such as fenugreek, aloe vera, and capsaicin—have supportive mechanistic studies and early clinical signals but lack large, independent RCTs focused specifically on alopecia.(PMC)

For henna and chebe, evidence primarily supports hair-shaft protection (reduced breakage, safer coloring) rather than direct follicle stimulation, with henna having one promising but animal-only alopecia model and chebe relying mostly on traditional practice and observational experiences.(ResearchGate)

An important limitation across nearly all studies is population bias: the majority of trials have been conducted in non-Afro-textured hair types, despite heavy usage of oils and herbal treatments in Black and Afro-Latine communities. Future research should specifically enroll tightly coiled hair types, protective styling practices, and hair-care regimens common in these groups to ensure that results translate to real-world use.(PMC)

From a formulation standpoint, oil blends that combine follicle-active botanicals (e.g., ginseng, rosemary, pumpkin seed, amla) with shaft-protective herbs (henna, chebe, fenugreek, aloe) may be particularly attractive: the former target the hair cycle, while the latter reduce breakage and support length retention—two sides of the same “hair growth” coin.

Conclusion

Recent research confirms that several plant-derived oils and extracts can play meaningful roles in hair-growth strategies. Amla, ginseng, rosemary oil, and pumpkin seed oil show the most robust evidence for improving hair growth metrics, while fenugreek, aloe vera, and capsaicin are emerging actives with promising but still limited data. Henna and chebe appear to primarily support hair by protecting the shaft and reducing breakage, which is nonetheless crucial for visible length, especially in highly curly and Afro-textured hair.

For formulators and practitioners, the current literature supports using botanical hair growth oils as adjuncts rather than replacements for evidence-based medical therapies, with attention to patch testing, scalp tolerance, and potential oral supplement interactions. Carefully designed, diverse, and longer-term clinical trials are needed to clarify optimal combinations, doses, and delivery systems—especially for communities that rely heavily on natural oils for cultural, economic, and health reasons.

References

(All references are from 2020–2025 and/or recent reviews summarizing earlier primary trials.)

Akhbari, M., Firooz, A., Rahimi, R., Shirzad, M., Esmaealzadeh, N., & Shirbeigi, L. (2024). The effect of an oral product containing amla fruit (Phyllanthus emblica L.) on female androgenetic alopecia: A randomized controlled trial. Journal of Ethnopharmacology, 318(A), 116958.(ScienceDirect)

Batiha, G. E. S., et al. (2023). Therapeutic potential of Lawsonia inermis Linn. [Review article].(PMC)

Cedirian, S., et al. (2025). The exposome impact on hair health: Non-pharmacological approaches to hair loss management. Journal of Cosmetic Dermatology.(ScienceDirect)

Elnady, R. E., Abdon, M. S., Shaheen, H. R., Eladawy, R. M., & Azar, Y. O. (2025). The future of alopecia treatment: Plant extracts, nanocarriers, and 3D bioprinting in focus. Pharmaceutics, 17(5), 584.(PMC)

Faisal, Z., Irfan, R., Akram, N., Manzoor, H. M. I., Aabdi, M. A., Anwar, M. J., et al. (2024). The multifaceted potential of fenugreek seeds: From health benefits to food and nanotechnology applications. Food Science & Nutrition, 12(4), 2294–2310.(PMC)

Jung, S. W., et al. (2025). Protective effects of Korean red ginseng against oxidative hair damage in an in vitro human hair follicle organ culture model. Annals of Dermatology.(Annals of Dermatology)

Kanwal, S. S., Wazir, A., Fatima, N., Ghauri, A. O., et al. (2024). Effect of Lawsonia inermis Linn in the treatment of alopecia. Journal of Xi’an Shiyou University (Natural Science Edition), 20(1), 360–372.(ResearchGate)

Natarelli, N., Gahoonia, N., & Sivamani, R. K. (2023). Integrative and mechanistic approach to the hair growth cycle and hair loss. Journal of Clinical Medicine, 12(3), 893.(MDPI)

Patel, M. N., Tuli, N., Patel, N., & Merja, A. (2025). Rosmagain™ as a natural therapeutic for hair regrowth and scalp health: A double-blind, randomized, three-armed, placebo-controlled clinical trial. Cureus, 17(6), e85906.(PubMed)

Prananda, A. T., et al. (2023). Phyllanthus emblica: A comprehensive review of its traditional uses, phytochemistry, and pharmacology. Frontiers in Pharmacology, 14, 1288618.(Frontiers)

Truong, V.-L., & Jeong, W.-S. (2021). Hair growth-promoting mechanisms of red ginseng extract through stimulating dermal papilla cell proliferation and enhancing skin health. Preventive Nutrition and Food Science, 26(3), 275–284.(KCI)

Truong, V.-L., et al. (2021). Red ginseng oil promotes hair growth and protects skin in mouse models. Journal of Ginseng Research.(ScienceDirect)

Wongrakpanich, A., et al. (2022). Phyllanthus emblica extract-loaded transfersomes for hair follicle targeting. Journal of Oleo Science, 71(7), 925–936.(J-STAGE)

Xiao, T., et al. (2023). TRPV1: A promising therapeutic target for skin aging and alopecia. Frontiers in Pharmacology, 14, 1037925.(Frontiers)

Zhu, J., et al. (2024). Study on the application of aloe vera in cosmetology and dermatology. Journal of Cosmetic Dermatology.(ScienceDirect)