Supplements for hair and skin: what the human evidence shows

63 supplements in our encyclopedia have at least one graded human outcome for hair and skin. Each row shows the strongest one, ranked by grade and then by the number of people studied. A high grade means the research is solid, not that the effect is large: open the row for the size of the effect and the dose tested.

Library last checked Supplement & Nutrient Encyclopedia How we grade evidence

Graded for hair & skin
63
Best grade
B
Articles
8
Related pages
1

Best grade for hair & skin

Strongest trial per supplement

Each supplement is shown once, at its best grade for hair and skin. The number is how many people were in that strongest study; for a meta-analysis, all its trials combined.

Grade A0 supplements

At least two concordant randomized controlled trials (RCTs), or a meta-analysis of RCTs, with a combined total of 300 or more participants.

No supplement reaches grade A for hair and skin yet.

Grade B2 supplements

At least one adequately powered RCT, or a consistent set of smaller RCTs.

Grade C21 supplements

Small or short RCTs, or trials with mixed results.

Show all 21Show fewer
Grade D38 supplements

A single small trial, or uncontrolled human data (open-label, before-and-after).

Show all 38Show fewer
No effect2 supplements

Adequately powered RCTs that found no effect on the outcome.

Grades run A to D per compound and outcome, never per product.

Compounds for hair & skin

Every encyclopedia entry with a graded human outcome for hair and skin: its strongest outcome, the study behind it and the form tested.

Hair & skin compounds, graded

Strongest first · 63 entries
Supplements with graded human evidence for hair and skin, strongest first
SupplementGrade for hair & skinStrongest outcomeStudy
Niacinamide (nicotinamide)Vitamin · checked Oct 21, 2026Grade BNew non-melanoma skin cancersImproved · Form tested: NicotinamideRCT n = 386 20154 graded rows for this goal
Hyaluronic AcidOther · checked Oct 21, 2026Grade BSkin hydration, elasticity and wrinkle depthImproved · Form tested: High-molecular-weight sodium hyaluronate (1.8 MDa) drinkRCT n = 147 20252 graded rows for this goal
Collagen peptidesOther · checked Oct 21, 2026Grade CSkin hydration, elasticity and wrinklesMixed · Form tested: Collagen supplementsMeta-analysis n = 1,474 2025
Tea Tree OilBotanical · checked Oct 21, 2026Grade CAcne severityImproved · Form tested: Topical tea tree oil preparationsMeta-analysis n = 445 20267 graded rows for this goal
Calendula (Calendula officinalis)Botanical · checked Oct 21, 2026Grade CSevere acute radiation skin reactions vs aqueous cream (breast cancer radiotherapy)No effect · Form tested: Calendula cream (Weleda)RCT n = 411 20138 graded rows for this goal
AstaxanthinOther · checked Oct 21, 2026Grade CSkin moisture, elasticity and wrinklesImproved · Form tested: Astaxanthin (mostly Haematococcus algal extract)Meta-analysis n = 293 2021
ComfreyBotanical · checked Oct 21, 2026Grade CTime for fresh abrasions to close: 10% vs 1% herb creamImproved · Form tested: Comfrey herb cream (Traumaplant 10%) vs an otherwise identical 1% creamRCT n = 278 20074 graded rows for this goal
Ophiopogon (Mondo Grass Root)Botanical · checked Oct 21, 2026Grade CAtopic dermatitis severity and flare-ups (topical use)Improved · Form tested: Topical product with oligofructans from Ophiopogon japonicusRCT n = 234 2019
DMSO (dimethyl sulfoxide)Other · checked Oct 21, 2026Grade CHerpes zoster course with idoxuridine carried in DMSO vs oral acyclovirImproved · Form tested: 40% idoxuridine in DMSO on the skin vs oral acyclovir (double-dummy)RCT n = 171 19928 graded rows for this goal
Purple nutsedge (Cyperus rotundus)Botanical · checked Oct 21, 2026Grade CUnderarm hyperpigmentationImproved · Form tested: Topical Cyperus rotundus essential oilRCT n = 153 20223 graded rows for this goal
PABA (Para-Aminobenzoic Acid)Other · checked Oct 21, 2026Grade CSkin thickening and mobility in sclerodermaNo effect · Form tested: Aminobenzoate potassiumRCT n = 146 1994
Glutathione (oral)Other · checked Oct 21, 2026Grade CSkin lightening and dark-spot sizeImproved · Form tested: glutathione 250 mg with L-cystine 500 mg, vs glutathione alone, cystine alone or placeboRCT n = 124 20223 graded rows for this goal
Gotu kolaBotanical · checked Oct 21, 2026Grade CFacial wrinkles and skin barrier in middle-aged womenImproved · Form tested: Oral Centella asiatica extractRCT n = 112 20262 graded rows for this goal
Equol (S-equol)Other · checked Oct 21, 2026Grade CCrow's-feet wrinklesImproved · Form tested: Natural S-equol 10 or 30 mg/day vs placeboRCT n = 101 2012
Rosemary OilBotanical · checked Oct 21, 2026Grade CHair count in pattern hair loss (androgenetic alopecia)Improved · Form tested: Rosemary oil applied to the scalpRCT n = 100 20152 graded rows for this goal
Yeast mannanOther · checked Oct 21, 2026Grade CSubjective skin drynessImproved · Form tested: Yeast mannan tablets vs maltose placeboRCT n = 100 2020
TriphalaBotanical · checked Oct 21, 2026Grade CScalp oiliness (sebum) in scalp seborrhoeaImproved · Form tested: Triphala powder standardised to about 92 mg gallic acid per gramRCT n = 80 2022
Pumpkin seed oilBotanical · checked Oct 21, 2026Grade CHair count in male pattern hair lossImproved · Form tested: pumpkin seed oil capsulesRCT n = 76 2014
Ceramides (oral phytoceramides)Other · checked Oct 21, 2026Grade CDry skin, water loss and wrinklesImproved · Form tested: Wheat polar lipid complex (oil or powder)RCT n = 72 20247 graded rows for this goal
Gamma-oryzanolOther · checked Oct 21, 2026Grade CSkin water contentImproved · Form tested: Rice bran oil capsules enriched with gamma-oryzanol and phytosterol estersRCT n = 70 2026
Ferulic acidOther · checked Oct 21, 2026Grade CRosacea lesions with topical ferulic acid added to doxycyclineImproved · Form tested: Topical ferulic acid solution vs saline, both with oral doxycyclineRCT n = 60 20252 graded rows for this goal
Lactobacillus salivarius (Ligilactobacillus salivarius)Other · checked Oct 21, 2026Grade CEczema severity in children (SCORAD)Improved · Form tested: L. salivarius plus fructo-oligosaccharide vs fructo-oligosaccharide aloneRCT n = 54 2012
Polypodium leucotomosBotanical · checked Oct 21, 2026Grade CRepigmentation with light therapyMixed · Form tested: Polypodium leucotomos extractRCT n = 50 20076 graded rows for this goal
ArnicaBotanical · checked Oct 21, 2026Grade DContact allergy to arnica in dermatology patientsWorsened · Form tested: Arnica extract patch testObservational n = 443 20015 graded rows for this goal
YarrowBotanical · checked Oct 21, 2026Grade DEpisiotomy wound pain and redness (ointment)Improved · Form tested: Yarrow ointment applied to the woundRCT n = 140 2018
Aloe VeraBotanical · checked Oct 21, 2026Grade DSkin barrier, moisture and collagen scoreImproved · Form tested: Aloe sterol capsules (lophenols and cycloartanols from aloe gel)RCT n = 120 2020
HorsetailBotanical · checked Oct 21, 2026Grade DEpisiotomy wound recovery and pain (3% ointment)Improved · Form tested: 3% Equisetum arvense ointment (topical)RCT n = 108 2015
Bentonite ClayOther · checked Oct 21, 2026Grade DInfant diaper rash (cream on the skin)Improved · Form tested: Bentonite cream applied to the skin, versus calendula creamRCT n = 100 2015
KeratinOther · checked Oct 21, 2026Grade DFacial skin aging signs, hair gloss and nail hardnessImproved · Form tested: Feather keratin hydrolysate (at least 83.5% free L-amino acids)RCT n = 99 20253 graded rows for this goal
CistancheBotanical · checked Oct 21, 2026Grade DHair density in patterned hair loss (with Laminaria)Improved · Form tested: MK-R7: Cistanche tubulosa and Laminaria japonica extract complex (3:1)RCT n = 94 2015
JiaogulanBotanical · checked Oct 21, 2026Grade DHair density, thickness and elasticityImproved · Form tested: Gynostemma pentaphyllum extract drinkRCT n = 94 2025
Melon SOD (GliSODin)Botanical · checked Oct 21, 2026Grade DSunburn threshold (minimal erythema dose)Improved · Form tested: Melon concentrate (Extramel-type, no gliadin)RCT n = 88 2018
PiceatannolOther · checked Oct 21, 2026Grade DFacial skin hydration and wrinklesImproved · Form tested: Drink with piceatannol from passion fruit seedsRCT n = 82 20262 graded rows for this goal
Green mandarin extractBotanical · checked Oct 21, 2026Grade DEye-area wrinkles in women (green mandarin extract)Improved · Form tested: Green mandarin (Putgyul) 50% ethanol extract standardized to narirutin (about 40 mg/g)RCT n = 80 2022
PygeumBotanical · checked Oct 21, 2026Grade DHair density in telogen effluvium and pattern hair loss (combination product)Improved · Form tested: Capsule with L-cystine, saw palmetto, pumpkin seed, Pygeum africanum, vitamins and mineralsRCT n = 80 2025
ErgothioneineAmino acid · checked Oct 21, 2026Grade DSkin moisture and wrinklesImproved · Form tested: Ergothioneine-rich oyster-type mushroom (hiratake, Pleurotus sp.) tabletsRCT n = 77 2024
Punicalagins (Pomegranate Ellagitannins)Botanical · checked Oct 21, 2026Grade DSunburn threshold (minimal erythema dose) after UVBImproved · Form tested: POMx extract (100 mg punicalagin A/B per 1,000 mg) or pomegranate juice vs placeboRCT n = 74 2019
Purslane ExtractBotanical · checked Oct 21, 2026Grade DChronic hand eczema severityImproved · Form tested: Standardized oral purslane syrup, plus topical Vaseline in both groupsRCT n = 62 2024
Saw palmettoBotanical · checked Oct 21, 2026Grade DHair counts in adults with thinning hairImproved · Form tested: Proprietary saw palmetto fatty-acid extract (SEREVELLE)RCT n = 60 2026
Eggshell membraneOther · checked Oct 21, 2026Grade DSkin firmness and elasticityImproved · Form tested: Fresh eggshell membrane (MKARE)RCT n = 58 2025
Sweet violet (Viola odorata)Botanical · checked Oct 21, 2026Grade DItch and dry skin in hemodialysis (topical oil with massage)Improved · Form tested: Violet oil applied with massageRCT n = 57 2019
AmlaBotanical · checked Oct 21, 2026Grade DHair growth in female pattern hair lossImproved · Form tested: Amla fruit syrup (Traditional Persian Medicine product)RCT n = 52 2024
BiotinVitamin · checked Oct 21, 2026Grade DBrittle nails (added to a medicated nail lacquer)Improved · Form tested: Oral biotin plus hydroxypropyl chitosan nail lacquer vs lacquer aloneRCT n = 50 2019
Silica (Silicon)Mineral · checked Oct 21, 2026Grade DSkin roughness and hair and nail brittlenessImproved · Form tested: Choline-stabilized orthosilicic acid (ch-OSA) pelletsRCT n = 50 20053 graded rows for this goal
Pantothenic Acid (Vitamin B5)Vitamin · checked Oct 21, 2026Grade DSkin wound repair after surgery (with vitamin C)No effect · Form tested: Pantothenic acid plus ascorbic acidRCT n = 49 19952 graded rows for this goal
Capsanthin (paprika xanthophylls)Other · checked Oct 21, 2026Grade DSunburn threshold (minimal erythema dose) and UV-induced darkeningImproved · Form tested: Paprika xanthophyll capsulesRCT n = 46 2018
Borage Oil (GLA)Fatty acid · checked Oct 21, 2026Grade DAcne lesionsImproved · Form tested: Borage oilRCT n = 45 20144 graded rows for this goal
SpearmintBotanical · checked Oct 21, 2026Grade DAndrogens and hirsutism in PCOSMixed · Form tested: Spearmint herbal teaRCT n = 42 20102 graded rows for this goal
OreganoBotanical · checked Oct 21, 2026Grade DBacteria and infection in surgical woundsImproved · Form tested: 3% oregano extract ointment versus petrolatumRCT n = 40 2011
RutinOther · checked Oct 21, 2026Grade DSkin wrinkles and elasticity (rutin cream applied to the skin)Improved · Form tested: Rutin-containing cream (concentration not stated in the abstract)RCT n = 40 2016
Ellagic AcidOther · checked Oct 21, 2026Grade DSkin darkening after UV exposureMixed · Form tested: Ellagic acid-rich pomegranate extractRCT n = 39 2006
Terminalia chebula (haritaki)Botanical · checked Oct 21, 2026Grade DFacial sebum, redness and wrinklesImproved · Form tested: Standardised fruit extract (Synastol TC)RCT n = 38 2023
SqualeneFatty acid · checked Oct 21, 2026Grade DFacial wrinkles and markers of skin photoagingMixed · Form tested: Oral squaleneRCT n = 37 2009
Rose HipBotanical · checked Oct 21, 2026Grade DFacial wrinkles, skin moisture and elasticityImproved · Form tested: Hyben Vital rose hip powder (seeds and shells), compared with astaxanthinRCT n = 34 2015
DL-PhenylalanineAmino acid · checked Oct 21, 2026Grade DSkin repigmentation in vitiligo with UVA lightImproved · Form tested: Oral L-phenylalanine plus UVA irradiationRCT n = 32 19942 graded rows for this goal
DMAE (Deanol)Other · checked Oct 21, 2026Grade DSkin firmness with DMAE gelImproved · Form tested: Topical DMAE gelRCT n = 30 2002
Castor OilBotanical · checked Oct 21, 2026Grade DEyelid inflammation (blepharitis) signs and symptomsImproved · Form tested: Topical 100% cold-pressed castor oil on the eyelidsRCT n = 26 2021
L-HistidineAmino acid · checked Oct 21, 2026Grade DAtopic dermatitis severity (SCORAD and patient-rated POEM)Improved · Form tested: L-histidine dissolved in a morning drinkCrossover RCT n = 24 2017
Marshmallow RootBotanical · checked Oct 21, 2026Grade DAtopic dermatitis severity in children (1% ointment)Improved · Form tested: 1% marshmallow ointment (topical) vs 1% hydrocortisone ointmentPilot RCT n = 22 2021
GuggulBotanical · checked Oct 21, 2026Grade DInflammatory lesions in nodulocystic acne versus tetracyclineImproved · Form tested: Gugulipid tabletsRCT n = 20 1994
Chlorophyll (Chlorophyllin)Other · checked Oct 21, 2026Grade DFine lines, wrinkles and sun spots on the face (topical gel)Improved · Form tested: 0.066% liposomal sodium copper chlorophyllin gel (topical)Open-label trial n = 10 20153 graded rows for this goal
Omega-6 Fatty AcidsFatty acid · checked Oct 21, 2026No effectEczema symptoms with GLA oilsNo effect · Form tested: Oral evening primrose oil or borage oil (sources of gamma-linolenic acid)Meta-analysis n = 1,596 2013
Evening primrose oilFatty acid · checked Oct 21, 2026No effectGlobal eczema symptomsNo effect · Form tested: Oral evening primrose oilSystematic review n = 289 2013
Grades follow our methodology. A “no effect” grade means good trials found no benefit. Amounts in trials are what was studied, not advice for you. What each costs a month at the studied dose: Evidence per Dollar.

Articles

Research reads built on the graded evidence above, for the supplements in this hub.

Research reads

8 articles

Find the evidence

Ask our graded human trials about a goal, a grade, a trial size, two supplements or a medicine. Answers are assembled on your device from the rows.

Evidence finder

3,342 trial rows · 869 interaction rows

76 graded trial rows on hair loss or skin that showed a benefit, across 53 supplements. Best grade among rows showing a benefit: B.

Grades of the 76 rows: B 2C 27D 47

Strongest row showing a benefit, per supplement

  1. Niacinamide (nicotinamide)Grade B

    New non-melanoma skin cancers

    Improved · 386 people · RCT · 2015 · 1 more matching row

  2. Hyaluronic AcidGrade B

    Skin hydration, elasticity and wrinkle depth

    Improved · 147 people · RCT · 2025 · 1 more matching row

  3. Tea Tree OilGrade C

    Acne severity

    Improved · 445 people · Meta‑analysis · 2026 · 2 more matching rows

Assembled from 76 graded trial rows when this page was built.

Fixed sentence templates filled from our rows; every line links to its row. Not medical advice.

Educational information only, not medical advice. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease.

Educational only. Not medical advice. Some links earn us a commission: kymatahealth.com/affiliate-disclosure.