Evidence
Biotin only helps with hair if you're actually deficient, which is rare.
Biotin only helps with hair if you're actually deficient, which is rare. No supplement has been shown to shorten telogen effluvium in well-nourished people.
The biotin myth needs to die. Biotin only helps with hair if you’re actually deficient, which is rare in adults eating a normal diet. No supplement has been shown in randomised trials to shorten telogen effluvium in well-nourished people.
Worse, high-dose biotin can interfere with thyroid blood tests (it can cause falsely-low or falsely-high readings depending on the assay). Thyroid dysfunction is a real cause of hair loss that we want to rule out, and biotin makes that ruling-out harder.
Things that actually help when low: iron (ferritin), vitamin D, B12, zinc, but only if you’re deficient. Get the bloods done first; supplement to fix actual deficiencies.