Osteopontin

Hairy moles are hairy because senescent pigment cells release osteopontin, which woke hair stem cells in mice and stimulated human follicles in culture, while a modified fragment of the same protein did the opposite.

Research chemical, not approved Cost varies

What it is

A secreted signalling protein made by many cell types. It is not an approved drug and no hair product is on the market.

How it works

In mouse models of moles, clusters of senescent pigment cells in the dermis released signals; osteopontin was necessary and sufficient to push hair stem cells out of dormancy, acting through the CD44 receptor. A different, modified osteopontin-derived peptide (FOL-005) pushed human follicles into early regression, partly by lowering FGF7.

What the studies show

Injecting or overexpressing osteopontin induced robust hair growth in mice. It was also overexpressed in human hairy moles and stimulated new growth of human follicles. A patent was filed by the authors' university. Mice and human tissue in culture only. Wang 2023
FOL-005 at 60 nM to 3 micromolar promoted early regression of human follicles in culture without stem-cell loss or toxicity, and was proposed for unwanted hair growth. Alam 2020
No human clinical trial of osteopontin for hair growth was found.

How it's used in studies

Injection into mouse skin and micromolar peptide in follicle culture. No human dosing exists.

Side effects and safety

Unknown for hair use. Osteopontin is also linked to tumour progression and inflammation in other research, which argues for caution.

Bottom line

Mechanistically fascinating, but animal and lab data only and not a usable product. Discuss with a doctor.

Fun facts

Hairy moles are hairy because senescent pigment cells signal to nearby hair stem cells with osteopontin. Wang 2023
A fragment from the same protein family stops hair growth instead. Alam 2020

Studies 2

Wang X et al. Signalling by senescent melanocytes hyperactivates hair growth. Nature. 2023

Design: animal
Who: mouse models of moles plus human hairy nevi and follicle culture

Result: Osteopontin from senescent nevus melanocytes drove hair growth via CD44; injecting it induced hair growth in mice and stimulated human follicles in culture.

Read the study ↗

Alam M et al. An osteopontin-derived peptide inhibits human hair growth at least in part by decreasing FGF7 expression. Br J Dermatol. 2020

Design: in vitro
Who: human scalp follicle organ culture and xenografts

Result: FOL-005 peptide promoted early regression (catagen) without stem-cell loss or toxicity.