How to take it

• Dose: Take it exactly as the label or your prescriber says. Most combination tablets are one tablet once or twice a day.
• Timing: Take it with or just after a meal. Zinc on an empty stomach often causes nausea or stomach upset. Vitamin E is fat-soluble, so it absorbs better with food that has some fat.
• Swallowing: Swallow it whole with a full glass of water. Don't crush or chew it unless the label allows.
• Spacing from other medicines: Zinc binds some drugs and lowers their absorption. Leave at least 2 hours between zinc and:
  • tetracycline and quinolone antibiotics (such as doxycycline and ciprofloxacin)
  • iron and calcium supplements
  • penicillamine
  Zinc and iron or calcium also compete for absorption, so take them at different times of day.
• Missed dose: Take it when you remember. Skip it if your next dose is close. Don't double up.

Dose limits

• Adults should not take more than 40 mg of zinc a day from all sources. The NIH fact sheet gives this as the upper limit. The NHS advises no more than 25 mg a day of supplement unless a doctor says otherwise. These limits don't apply when a doctor prescribes zinc for a medical reason.
• Elemental zinc is not the same as the salt weight. A 220 mg zinc sulfate tablet contains only 50 mg of elemental zinc (Dermatology 2-Volume Set 5e, Zinc). Check which figure your label lists.
• The upper limit for vitamin E from supplements is generally 1,000 mg a day of alpha-tocopherol (about 1,500 IU natural form). Most combination tablets contain much less.
• The AREDS2 eye formula is a prescribed-style regimen for macular degeneration. It uses vitamin E 400 IU and zinc 25 to 80 mg, with copper 2 mg (Kanski's Clinical Ophthalmology, 10th ed., AREDS2). Don't copy it unless an eye doctor advised it.

Side effects

• Zinc: nausea, vomiting, stomach upset, headache, dizziness, and a metallic taste. Long-term high doses (about 50 mg a day or more) can cause copper deficiency, with anaemia and numbness or weakness in the limbs (Yamada's Textbook of Gastroenterology, 7th ed., Zinc). Very high doses can also lower HDL cholesterol and immunity, according to the NIH consumer sheet.
• Vitamin E: high doses have an antiplatelet effect and have been linked to a higher risk of bleeding (see this review of vitamin and mineral safety).

Check with a doctor first if you:

• take warfarin, aspirin, clopidogrel or other blood thinners, because vitamin E adds to the bleeding risk
• are on chemotherapy or statins with niacin, since vitamin E may interfere
• have a bleeding disorder, upcoming surgery, or a history of stroke
• have kidney disease
• are pregnant or breastfeeding
• are giving it to a child, because doses are weight- and age-based

Common reasons and duration

Newer evidence

What counts as normal

Find the cause first

Treatments with real evidence

• Minoxidil 2% or 5% (topical): This works best in early, limited pattern loss. Responders must keep using it indefinitely (Andrews', Pattern Alopecia). Expect about 4 months before you see improvement (AAD). A temporary extra shed in the first weeks is common.
• Finasteride 1 mg daily (men only): It stops further loss in up to 90% of men over 5 years, and about 65% regrow hair. Benefits are lost if you stop (Andrews'). It needs a prescription and a discussion of side effects. It is not for women who may become pregnant.
• Topical minoxidil and oral finasteride are the only FDA-approved drugs for pattern hair loss (Cummings Otolaryngology, Key Points). Stopping minoxidil can trigger shedding 3 to 4 months later (Goldman-Cecil Medicine).

Typical composition of hair tablets

• biotin (vitamin B7)
• zinc
• iron
• vitamin D
• vitamin E and vitamin C
• B vitamins (B6, B12, folate)
• sometimes amino acids (such as L-cysteine) or marine protein

• Zinc: Deficiency causes hair loss, and supplementing corrects it (Fitzpatrick's Dermatology, Zinc Deficiency).
• Biotin: Deficiency is rare, because it is found in many foods and made by gut bacteria (Henry's Clinical Diagnosis). A 2024 review of biotin found no high-quality evidence that it helps hair in people who are not deficient. Biotin can also falsely alter thyroid and troponin blood tests (Tietz Textbook of Laboratory Medicine), so tell the lab if you take it.
• Iron: Supplement only if your ferritin is low. The link between low ferritin and chronic diffuse shedding is disputed (Fitzpatrick's references).
• A 2024 systematic review of micronutrients (PMID 39440586) and a 2026 systematic review of diet and hair (PMID 40836838) support this. Neither shows that random multivitamins stop hair loss. The benefit is mainly in correcting a documented deficiency.

What to do

1. Eat enough protein, iron and calories. Crash diets cause shedding (Andrews', Fig. 33.4).
2. Ask for blood tests if shedding is heavy or lasts more than 3 months: CBC, ferritin, TSH, vitamin D, B12, and zinc. In women, add androgen tests if there are irregular periods or acne.
3. Treat pattern thinning early with minoxidil, plus finasteride for men, under a dermatologist.
4. Be gentle with the hair. Avoid tight hairstyles, heat styling, and harsh chemical treatments. Treat dandruff if you have it.
5. Give it time. Hair cycles are slow, and any treatment needs 3 to 6 months before you can judge it.

See a doctor soon if

• you have patchy bald spots, or scarring, redness or pain of the scalp
• there is sudden heavy loss
• you also have fatigue, weight change, or irregular periods
• you are a woman with thinning and acne or excess facial hair
• shedding lasts more than 6 months