Verbatim response from Perplexity
Usually, hair growth supplements only help if your hair loss is tied to a nutrient deficiency; otherwise, the evidence is weak. For common pattern hair loss, prescription or proven OTC treatments like minoxidil often have stronger evidence than supplements.[1][2][9][14]
What the evidence says:
- Biotin is widely marketed, but it has not been proven effective for hair growth in people without a deficiency.[1][17]
- Collagen may help hair feel thicker or healthier, but evidence that it regrows hair is inconclusive.[1]
- In general, there is little clinical evidence that typical hair vitamins/supplements improve hair growth unless you have a documented deficiency such as low iron, vitamin D, or zinc.[2][9][14][15]
- Some specific multi-ingredient products have shown promising short-term results in trials, but the evidence is still limited and not strong enough to replace standard treatments.[8][9][16]
When prescription treatment is more likely to help:
- If you have pattern hair loss (male or female pattern thinning), supplements alone usually are not enough.[9][14]
- Dermatologists recommend getting an accurate diagnosis first, because treatment depends on the cause of hair loss.[10][13]
Practical rule of thumb:
- Try supplements if testing shows a deficiency or your clinician thinks one is contributing to shedding.[4][14][15]
- See a dermatologist if you have ongoing thinning, widening part, receding hairline, patchy loss, or shedding that lasts more than a few months, because you may need prescription treatment rather than vitamins.[10][13]
If you want, I can help you compare minoxidil vs finasteride vs popular supplements for your specific type of hair loss.