The hair supplement industry is worth billions of dollars, and most of it runs on hope and clever marketing. I’m not saying all supplements are useless — some genuinely help. But the gap between what’s promised and what’s proven is wider than most people realize.
The ones that actually have evidence
Iron — if you’re deficient (and many women are). Low ferritin is one of the most common correctable causes of hair thinning. Get tested before supplementing, because too much iron is harmful.
Vitamin D — if you’re deficient (and if you live in Chicago, you probably are from November through April). Evidence links low vitamin D to hair loss and follicle dormancy. Again, test first, supplement based on results.
Zinc — if you’re deficient. Important for follicle function and cell division. Vegetarians and people with gut issues are most at risk for deficiency.
Omega-3 fatty acids — modest evidence for improved hair density and reduced inflammation. Low risk, generally beneficial for overall health regardless of hair effects.
Notice the pattern? The supplements with real evidence all work by correcting a deficiency. If you’re not deficient, supplementing won’t do much.
The ones that are overhyped
Biotin. The poster child of hair supplements. Here’s the thing: biotin deficiency is genuinely rare in people eating a normal diet. Your gut bacteria produce it. It’s in eggs, nuts, and dozens of other common foods. The evidence that supplementing biotin improves hair in non-deficient people is essentially nonexistent.
What biotin supplementation does do: mess up your lab work. It can interfere with thyroid tests, troponin tests (heart), and other important bloodwork. If you’re taking biotin, tell your doctor before any lab testing.
Collagen. Popular, but the evidence for hair specifically is thin. Your body breaks collagen down into amino acids during digestion — it doesn’t just route those amino acids to your hair follicles. You’d get the same amino acids from eating chicken.
Specialty hair gummies. Most are just biotin and some B vitamins in a gummy format with a markup. Check the ingredient list — if it’s mainly biotin, B vitamins, and sugar, save your money.
The “proprietary blend” red flag
If a supplement lists a “proprietary blend” without telling you how much of each ingredient is in it, that’s a red flag. It usually means the active ingredients are present in amounts too small to be effective, padded with cheap fillers. Legitimate supplements list exact dosages of every ingredient.
What I recommend instead
Get bloodwork done. Test iron/ferritin, vitamin D, thyroid, zinc. Fix what’s actually low. Eat adequate protein (your hair is made of protein — if you’re not eating enough, no supplement replaces that). Stay hydrated.
For topical improvement, K18 and Davines Naturaltech Energizing do more for your hair than any gummy ever will. They work where the hair actually is, not in your digestive system.
Spend your supplement budget on a good blood panel and a consultation with your doctor. Then spend the rest on products that actually work topically. Book at Reverie and we’ll tell you honestly what your hair needs.
