sh-Polypeptide-86 is a cosmetic ingredient in scalp serums for thinning hair: a lab-made copy of follistatin, a natural protein that blocks signals holding hair follicles at rest. The idea is sound in animals, but no study has tested the ingredient on the scalp, and no regrowth effect is shown in people. Expected harm is low; the more concrete cost is time, as hair loss progresses and better-supported options exist. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Standardized scalp photographs / target-area hair count | No established target; stable or rising versus own baseline | Objective efficacy endpoint |
| Ferritin | 50–100 ng/mL | Iron stores; low levels drive shedding |
| TSH (thyroid-stimulating hormone) | 0.5–2.5 mIU/L | Thyroid dysfunction causes diffuse loss |
| 25-hydroxyvitamin D | 40–60 ng/mL | Deficiency is linked to hair loss |
| Zinc (serum) | 90–120 µg/dL | Deficiency can cause shedding |
| Hemoglobin | Women 13.5–15.0 g/dL; men 14.0–16.0 g/dL | Detects anemia contributing to shedding |
| Total testosterone (women with androgen signs) | 15–40 ng/dL | Excess androgen accelerates pattern loss |
| Scalp skin examination | No new or changing lesions | Screens for skin cancer and dermatitis |
Cadence: Baseline before starting; photographs at 3 and 6 months, then every 6 months; blood tests at 6–12 months if a baseline value was abnormal, otherwise yearly; scalp skin examination every 12 months (every 6 months after prior skin cancer)