Biotin is the cheapest, most-recommended hair supplement on the market — and a real cornerstone of keratin production. Every quality hair supplement contains it, including the one at #1 on this list.

The problem isn't biotin itself. It's that GLP-1 medications slow how quickly food empties from the stomach by 30 to 70%. That same slowdown affects how supplements are absorbed. A woman taking 5,000 or even 18,000 mcg of standard biotin on a GLP-1 isn't getting the dose her body would have absorbed before the medication.

This explains the feedback that comes up most often: "Early on it seemed to help, not much anymore" (Gary) and "Hair vitamins, biotin, nothing works."

For women dealing with garden-variety nutritional thinning, standalone biotin can move the needle. For women on GLP-1s, it needs to be paired with pre-digested co-factors that can actually be absorbed. On its own, it isn't suitable for this specific situation.

→ Available at any drugstore. Typical price: $8–$25.

Weem has built a strong following thanks to social media and a clean, vegan, gluten-free formulation. For mild thinning from age or stress, the reviews suggest it can deliver. It's the gummy many women turn to when their drugstore biotin stops working.

For women on GLP-1s specifically, the responses are more mixed. Francine, wrote "Weem seems to be working a little" — and that "a little" is the pattern. A small initial bump, then a plateau.

Two reasons. First, the same absorption issue from #5: it's a multivitamin and biotin stack, even harder to absorb in gummy form on slowed digestion. Second, gummies have to fit sugar and binders alongside the actives, so doses tend to run lower than capsule equivalents.

Weem isn't a bad product. It just isn't the right tool for GLP-1 hair loss.

→ Available at weemco.com. Typical price: $30.

Collagen has genuine evidence for skin elasticity and joint support. Many women migrate it over to hair on the logic that if it helps nails and skin, it should help hair too.

What gets reported most often: "Collagen — didn't work" (Alanna), "Collagen peptides, biotin and many others, nothing worked," and "Biotin, collagen, nothing worked" (Linda).

Collagen delivers amino acid building blocks — useful when the follicle is actively trying to build and just needs more raw material. On a GLP-1, the more fundamental issue is that the follicle's growth signal has been quieted. You can deliver all the building materials in the world, but if the construction crew isn't getting the work order, nothing gets built.

For women not on GLP-1s, collagen is a reasonable addition. For women on these medications, it's a missing-half solution.

→ Available widely. Typical price: $25–$45.

Nutrafol is the supplement women feel most disappointed by, because they trusted it the most. Dermatologist-recommended, sold at Sephora, roughly $88 a bottle, with a serious multi-ingredient formulation including saw palmetto, marine collagen, and ashwagandha.

For hormonal thinning around perimenopause or DHT-driven hair loss, Nutrafol has real published results behind it. But for women on GLP-1s, the picture is different: "Tried Nutrafol and it didn't help" and Patricia, who wrote "Dermatologist recommends Nutrafol but price matters."

The reason is that Nutrafol was designed before GLP-1 medications became widespread. It targets DHT-driven thinning and stress-related shedding well — but GLP-1-induced hair loss is a different mechanism the formula wasn't built around. Add in the price, plus contraindications for women with shellfish allergies or vegan preferences (it contains marine collagen and shark-derived ingredients), and it isn't a fit for most women in this position.

→ Available at Sephora. Typical price: $88.