A lab-made copy of a natural growth signal applied to the scalp. Biologically plausible for reawakening resting follicles, but no published human studies show it regrows scalp hair; evidence rests on lab and animal work. Absorbs poorly, so delivery matters. Generally well tolerated, with mild local irritation the main issue. Best seen as an early-stage add-on. (Full Review)

Protocol

Application

Once or twice daily

Leave-on serum applied to affected scalp areas

Delivery

Penetration-dependent

Needs a delivery system (e.g., liposomal encapsulation, microneedling)

Best Use

Clean, dry scalp

Avoid washing the area for several hours afterward

Time to effect

Earliest Visible Change

Months, not weeks

Hair cycles are slow; not to be judged before about three months

First Assessment

~12 weeks

Earliest point for meaningful assessment of response

Fuller Assessment

~24 weeks

Density and coverage best judged over months, not weeks

Benefits

Speculative: Stimulation of hair regrowth; prolongation of the active growth phase; protection of follicles from stress-induced loss; improved scalp microcirculation and skin quality

Contraindications

Pregnancy or breastfeeding

Active scalp infection, open wounds, or inflammatory scalp disease at the site

Known allergy to the product or its components

Active or recent skin cancer in the treatment area

Key Interactions

Topical retinoids (tretinoin, adapalene) and other irritating prescription topicals

Exfoliating acids (glycolic, salicylic acid) or benzoyl peroxide

High-strength vitamin C / antioxidant serums

Minoxidil and other growth-factor peptides (sh-Polypeptide-1/bFGF, copper tripeptide)

Microneedling and energy-based procedures

Risk & Side Effects

Low: Local skin reactions

Speculative: Allergic or hypersensitivity response to a recombinant protein; theoretical pro-proliferative / tumor-promotion concern; unintended effects from broad FGF signaling

Monitoring

Marker	Target	Why
Ferritin (iron stores)	50–70+ ng/mL	Low iron stores are a common, reversible driver of hair shedding
TSH (thyroid-stimulating hormone)	~0.5–2.5 mIU/L	Thyroid imbalance is a frequent treatable cause of diffuse hair loss
Vitamin D (25-hydroxyvitamin D)	40–60 ng/mL	Low vitamin D is associated with hair-cycle disruption
Total testosterone & DHEA-S	Sex- and age-appropriate optimal range	Androgen excess (especially in women) signals an androgen-driven component that a growth factor will not address
Zinc	Upper half of reference range	Zinc deficiency can contribute to hair loss and impaired follicle function

Cadence: Baseline labs once before starting, then re-test only if clinically indicated; objective hair assessment at baseline, ~12 weeks, ~24 weeks, and every 6 months thereafter

Qualitative Assessment

Reduced daily shedding (fewer hairs in the brush, shower, or on the pillow)
Increase in fine "regrowth" hairs along the hairline or part, then their thickening into coarser hairs over months
Subjective scalp coverage, part width, and ponytail thickness
Overall scalp comfort and absence of irritation as a tolerability marker

Sh-Polypeptide-11 for Hair Regrowth

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment