TABLE 1.

Summary of clinical studies evaluating the efficacy of natural ingredients in the treatment of alopecias

NATURAL INGREDIENTS	STUDY	MECHANISM	COMPARISON	ALOPECIA VARIANT	CONCLUSION	LEVEL OF EVIDENCE
Azelaic acid	Randomized, controlled trial11	Hypertrichosis and irritant contact dermatitis	Azelaic acid vs. anthralin	Alopecia areata	The use of azelaic acid gave similar results to anthralin with regard to hair regrowth, and can be an effective topical therapy for patchy AA.	IA
Garlic gel	Double blind randomized controlled study12	Unknown	Combination of garlic and betamethasone valerate cream vs. placebo group (only betamethasone valerate cream)	Alopecia areata	The number of total hair, terminal hairs, and size of hair patches were measured quantitively. The use of garlic gel significantly added to the therapeutic efficacy of topical betamethasone valerate starting the second month of application.	1
Olive oil	Case report13	Unknown	None	Psoriatic Alopecia	Dexamethasone 0.25% lotion applied BID, with combo of tar shampoo and olive oil applied before shampooing daily showed a significant improvement in reduction of scales and stabilization of hair shedding. 75% hair regrowth was achieved by 3 months after therapy and had no recurrence of alopecia at the 1-year follow-up.	IIIC
Pumpkin Seed Oil	Randomized, double blind, placebo-controlled trial23	5- alpha reductase antagonist, antiandrogenetic effect	Pumpkin seed oil vs. placebo	Androgenic Alopecia	At 12 and 24 weeks, there were 30% and 40% mean increases in hair counts from baseline in PSO-treated men and 5% and 10% increases in hair count in placebo-treated men, which resulted in significant net increase of 25% and 30% (both, P<0.001) at Weeks 12 and 24, respectively, in the intervention group as compared with the placebo group using phototrichography for comparison.	IA
Rosemary oil	Single-blind, randomized clinical trial14	Enhance microcapillary perfusion	Rosemary oil vs. 2% minoxidil ointment	Androgenic Alopecia	Application of rosemary oil was as effective as 2% minoxidil ointment. In addition, there was better treatment adherence in the rosemary group compared to the minoxidil group.	IA
Tea tree oil	Double-blind, randomized, placebo controlled study15	Anti-inflammatory properties	Formulation containing minoxidil, diclofenac, and tea tree oil vs. minoxidil alone vs. placebo group	Androgenic Alopecia	A multimodal microemulsion comprising minoxidil, diclofenac, and tea tree oil was significantly superior to minoxidil alone and placebo in terms of stability, safety, and efficacy, and achieved an earlier response in the treatment of androgenic alopecia compared with minoxidil alone in this 32-week pilot study.	1
COMBINATION AROMATHERAPY
NATURAL INGREDIENTS	STUDY	MECHANISM	COMPARISON	ALOPECIA VARIANT	CONCLUSION	LEVEL OF EVIDENCE
Thyme oil, rosemary oil, lavender oil, evening Primrose oil, atlas cedarwood oil	Double-blind placebo controlled study16	Unknown	A combination of the oils was mixed with the carrier oils, jojoba and grapeseed oils vs. placebo group (only carrier oils)	Alopecia areata	Led to clinically significant (moderate to dense) hair growth in up to 75% of patients, where placebo (same carrier oils without the aromatherapy) led to hair growth in up to 30% of patients. Hair regrowth was observed in 37 patients (93%) in both treatment and the control groups. However the response rate in the aromatherapy group was significantly higher than placebo group.	IA
Thyme oil, rosemary oil, lavender oil, cedarwood oil	Double-blind, randomized controlled study17	Unknown	A combination of the oils was mixed with the carrier oils, jojoba and grapeseed oils vs. control group (only carrier oils)	Alopecia areata	Nineteen (44%) of 43 patients in the active group showed improvement compared with 6 (15%) of 41 patients in the control group. Treatment with these essential oils was significantly more effective than treatment with the carrier oil alone.	IA

AA: alopecia areata; BID: twice daily