Verbatim response from Perplexity
It is usually not too late to treat hair loss, but it becomes harder to reverse once follicles have miniaturized significantly or scarred completely.[2][4][6] The earlier you start, the better the chance of slowing loss and preserving remaining hair.[2][4][8]
What matters most is the cause and how advanced the loss is.[1][2][7] In pattern hair loss, doctors often try finasteride and minoxidil early; if hair loss is already extensive, those treatments may still help preserve existing hair, but they are less likely to fill large bald areas.[1][2][5]
A practical rule of thumb is:
- Still worth treating: you have thinning, miniaturized hairs, or some visible regrowth.[5]
- Harder to treat with medication alone: loss is advanced and large areas are thin or bare.[2][5]
- Often needs specialist evaluation: hair loss is sudden, patchy, painful, inflamed, or comes with fatigue, weight change, fever, or other systemic symptoms.[1][4][6]
If follicles have stopped working or the scalp has scarring, regrowth becomes much less likely and a hair transplant may be the main option, if donor hair is adequate.[4][6] If the loss is from something reversible like telogen effluvium, treatment or removal of the trigger can lead to improvement, often within 3–6 months.[4][7]
For best results, a dermatologist or hair-restoration specialist can confirm the cause and tell you whether medication, lab work, or transplant is the right next step.[1][2][6]