Every hair regeneration programme in development, tracked.

Taken by mouth.

Applied to the scalp — solutions, foams, gels.

Delivered into or under the scalp by needle.

Antibodies, fusion proteins and peptides.

Live cells — usually the patient's own dermal papilla cells, multiplied in a lab and returned.

Growing new follicles rather than rescuing existing ones. The only approach that could restore hair to fully bald scalp.

male pattern baldness · common baldness · AGA

patchy hair loss · autoimmune hair loss · alopecia totalis · alopecia universalis

female pattern baldness · hair thinning in women · FPHL

sudden hair shedding · postpartum hair loss · stress hair loss · hair loss after illness

cicatricial alopecia · frontal fibrosing alopecia · lichen planopilaris · CCCA

hair loss from chemotherapy · chemo hair loss · permanent chemotherapy-induced alopecia

One small 2002 study in alopecia areata, with no repeat we could find. Nothing in pattern baldness.

One small 2015 trial against low-strength minoxidil, with no placebo group. It does not show rosemary works as well as minoxidil.

No study has tested rice water on hair growth. The one study of rice water measured how hair strands feel.

One placebo-controlled trial, in 76 men, paid for by the company that supplied the capsules, which may have contained more than pumpkin seed oil.

Small trials, two of them run or backed by companies selling an extract. The one head-to-head comparison found it did less than finasteride.

The best trial had no placebo and was paid for by Alpecin's maker. The UK advertising regulator ruled Alpecin's hair-loss claim misleading.

It helps people who lack biotin, which is uncommon. No good trial shows it helps anyone else, and high doses can distort blood tests.

We found no study testing castor oil alone on hair growth in people, on the scalp, eyebrows or eyelashes.

One study, in mice. We found no human trial of peppermint oil on hair growth.