Sh-Oligopeptide-1 is a lab-made copy of a natural skin-growth protein, sold in scalp serums for fuller hair. It reliably affects follicle cells in lab dishes, but visible hair regrowth in people has never been shown — and the same protein can push hair toward shedding. An experimental, biologically uncertain idea, not a proven approach. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Ferritin | 50–70 ng/mL | Low iron stores are a common, reversible cause of shedding that would confound any serum trial |
| TSH | 1.0–2.0 mIU/L | Thyroid dysfunction causes diffuse hair loss that mimics or masks other causes |
| Vitamin D (25-OH) | 40–60 ng/mL | Low vitamin D is associated with hair-cycle disturbance and is easily corrected |
| Serum zinc | Mid-to-upper reference range | Zinc deficiency can contribute to hair shedding |
Cadence: Observational; reassess at ~3 and ~6 months with standardized photographs, then every 6 months if continuing. Stop sooner if shedding or irritation increases.