By goal
Evidence-Backed Supplements for Skin and Hair
Plenty of pills promise glowing skin and thicker hair, but the evidence behind them ranges from solid to nonexistent. We grade each one against the human trials so you can see what genuinely helps skin hydration, elasticity, or hair growth versus what's mostly marketing. Nothing here treats a medical condition or replaces seeing a dermatologist.
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Best-supported here: Iron (Strong), Omega-3 (EPA/DHA) (Strong), Cantaloupe Melon (Moderate), Gotu Kola (Preliminary) — each graded below by the weight of human evidence.
| Supplement | Evidence for this goal | Typical dose | Key caution | Studies |
|---|---|---|---|---|
| Iron | Strong | Treatment ~40–60 mg elemental; alternate-day dosing may absorb better.… | Constipation, nausea and dark stools are common. | 17 |
| Omega-3 (EPA/DHA) | Strong | 1–2 g combined EPA+DHA/day; up to 4 g (Rx) for high triglycerides. | Safe at typical doses. | 20 |
| Cantaloupe Melon | Moderate | 1 cup diced (~160 g) to half a medium melon; ~150-300 g typical serving | Generally very safe as a food. | 9 |
| Gotu Kola | Moderate for this goal | ~500 mg twice daily of extract. | Generally well tolerated; possible drowsiness and GI upset. | 19 |
| Pear | Moderate | One medium pear (~178 g) provides ~5.5 g fibre, roughly a fifth of the… | Generally very safe. | 8 |
| Polypodium leucotomos | Moderate | 240–480 mg/day orally (often taken before sun exposure). | Well tolerated short-term with only occasional mild GI upset; long-term and pregnancy data… | 18 |
| Strawberry | Moderate | A typical serving is about 1 cup (152 g, ~8 medium berries) fresh. Card… | Generally very safe. | 10 |
| Vitamin C | Moderate | 75–90 mg/day RDA; 200 mg saturates tissues. Doses >1g mostly excreted. | Safe. | 21 |
| Ambarella | Preliminary | One medium fruit (about 60-100 g) eaten fresh, or 100-150 g in juice or… | Generally safe as a food. | 8 |
| Apricot | Preliminary | 1 cup halves (155 g) fresh, ~2-3 whole apricots; or ~30-40 g dried (a s… | The flesh is very safe. | 9 |
| Astaxanthin | Preliminary for this goal | 4–12 mg/day (most trials used 4–6 mg/day). | Generally well tolerated at 4–12 mg/day. | 20 |
| Cempedak | Preliminary | 1 serving of fresh pulp, roughly 100 g (about 4-6 arils) | Cempedak is a high-carbohydrate, moderate-energy fruit (~117 kcal/100 g) and can raise bloo… | 10 |
| Evening Primrose Oil (GLA) | Preliminary for this goal | Commonly 4–6 g oil/day (~320–480 mg GLA). | Generally well tolerated; mild, temporary GI upset is most common. | 16 |
| Gandaria | Preliminary | Culinary fruit; ~100 g (a small handful of 3–5 fruits) as a typical ser… | Generally safe as a food; rodent toxicity studies of fruit-extract yoghurt showed no advers… | 9 |
| Gooseberry | Preliminary | 1 cup raw (about 150 g), roughly 25-30 berries | Generally safe as food. | 8 |
| Honeydew Melon | Preliminary | 1 cup diced (~170 g); a typical wedge is one-eighth of a medium melon | Generally very safe. | 9 |
| Lycopene & Carotenoids | Preliminary | ~10–16 mg lycopene/day from tomato products for ≥10–12 weeks; effects b… | Dietary lycopene from foods is well tolerated; very high intake can cause harmless orange-t… | 19 |
| Mangosteen | Preliminary | 1 medium fruit (~3-4 segments of edible aril, ~40-60 g flesh); studied… | The fresh aril is generally safe as a food. | 9 |
| Passion Fruit | Preliminary | Pulp of 2-3 fruits (~36-55 g edible) as a whole-food serving. Studied b… | Generally safe as a food. | 9 |
| Phytoceramides | Preliminary for this goal | ~1.8–40 mg/day glucosylceramides (source-dependent). | Well tolerated in short trials at low doses, with no serious adverse events reported; evide… | 17 |
| Pomelo | Preliminary | 1 cup sections (~190 g); a whole medium fruit yields several cups of ed… | Like grapefruit, pomelo contains furanocoumarins that inhibit intestinal CYP3A4 and P-glyco… | 11 |
| Pulasan | Preliminary | 1–3 fresh fruits (~50–150 g edible aril); no studied therapeutic dose | Generally regarded as a safe edible fruit with no documented toxicity or drug interactions. | 11 |
| Pycnogenol (Pine Bark) | Preliminary for this goal | 75–150 mg/day (oral, often split). | Well tolerated in short trials (occasional mild GI upset, dizziness, headache); long-term d… | 18 |
| Rambutan | Preliminary | About 5-6 fresh fruit (~100 g edible flesh); flesh eaten raw, seed and… | Generally safe as food. | 9 |
| Salak (Snake Fruit) | Preliminary | 1-3 fresh fruits (~50-150 g edible flesh) as a snack; no established th… | Generally safe as a food. | 10 |
| Sapodilla (Ciku) | Preliminary | 1 medium fruit (~170 g); ~100-170 g fresh ripe pulp | Unripe fruit is high in astringent tannins and latex that can cause mouth irritation, throa… | 9 |
| Saw Palmetto | Preliminary for this goal | 320 mg/day of a lipophilic berry extract standardized to 85-95% fatty a… | Generally well tolerated; in trials adverse events (mild GI upset, headache, occasional dec… | 13 |
| Silica (Horsetail / ch-OSA) | Preliminary for this goal | ch-OSA ~10 mg Si/day (dose used in trials). | ch-OSA at ~10 mg Si/day was well tolerated in short trials and is unlikely to harm people w… | 15 |
| Starfruit (Carambola) | Preliminary | 1 medium fruit (~91 g) or ~100 g sliced; avoid entirely in chronic kidn… | CONTRAINDICATED in chronic kidney disease, end-stage renal disease, and dialysis patients—e… | 10 |
| Zinc | Preliminary for this goal | 8–11 mg/day RDA; up to 40 mg upper limit. Lozenges (75mg+/day) only sho… | Safe within limits (adult upper limit ~40 mg/day). | 21 |
| Collagen Peptides | Mixed for this goal | 10–15 g/day (skin); ~10 g/day or specialized peptides for joints. | Very safe. | 19 |
| Glutathione (Skin Whitening) | Mixed for this goal | Studied oral doses ~250–500 mg/day for 4–12 weeks; IV/injectable is the… | Oral glutathione at studied doses appears well tolerated short-term, but long-term cosmetic… | 18 |
| Hyaluronic Acid (Oral) | Mixed for this goal | 120–240 mg/day (most trials used 120 mg/day for 6–12 weeks). | Generally well tolerated in short trials (≤12 weeks) with no serious adverse events; long-t… | 17 |
| Niacinamide (Nicotinamide) | Mixed for this goal | Oral: 500 mg twice daily (chemoprevention). Topical: 2–5% in serums/cre… | Well tolerated and, unlike niacin (nicotinic acid), does NOT cause flushing — don't confuse… | 15 |
| Vitamin E (Tocopherol) | Mixed | RDA ~15 mg/day (22.4 IU); doses ≥400 IU/day raise safety concerns. | Topical vitamin E commonly causes contact dermatitis (~1 in 3 in the Baumann scar trial). | 20 |
| Biotin (Vitamin B7) | No Evidence | Adequate intake ~30 mcg/day; megadoses (5–10 mg) sold for hair. | Direct toxicity is very low (excess is excreted; no upper limit set). | 17 |
| He Shou Wu (Fo-Ti) | No Evidence for this goal | Traditionally used as prepared (processed) root in formulas; raw root i… | ⚠ Significant risk of liver injury (acute hepatitis), including with 'natural' products. | 17 |