A two-minute read — or switch to academic mode if you are a doctor or pharmacist.
About 1 cm a month. Each follicle cycles through growth (anagen), regression (catagen) and rest (telogen). Roughly nine in ten hairs on your head are growing right now, and they need nutrients every day.
Mean growth 0.35 mm/day (StatPearls) · anagen 2–7 years, catagen 2–3 weeks, telogen ~3 months · normal scalp anagen:telogen ≈ 85–90 : 10–15
Stress, illness, rapid weight loss or childbirth push many hairs into rest at once; they fall together about three months later. Most of it reverses on its own once the cause has passed.
Telogen effluvium: onset 2–4 months after trigger, shedding >100 hairs/day, resolves within 6–12 months once the trigger clears (Malkud 2015) · chronic TE >6 months warrants work-up: ferritin, TSH, vitamin D, zinc
When intake is short, the body feeds vital organs first, so hair is often the first place it shows. Complete, consistent intake matters more than a short burst.
Review-level evidence supports roles for iron (ferritin), zinc, vitamin D, biotin (deficiency only), selenium (deficiency and excess) and protein intake in the hair cycle (Almohanna 2019; Guo & Katta 2017) · excess vitamin A and selenium are associated with TE
Some nutrients — vitamin A and selenium among them — cause shedding when you take too much. U-TURN leaves out vitamin A and keeps every nutrient within Thai FDA limits.
Every nutrient in U-TURN sits within Thai FDA maximums for supplements · no retinol/β-carotene · selenium 55 mcg (79% Thai RDI) · chelated (bisglycinate) forms chosen for GI tolerability
Serums with alcohol, fragrance or menthol feel fresh, but can dry and irritate the scalp with continued use. ONE PEN leaves out all five.
Internal Evidence Review v2.0 (Oct 2026) compared 28 serums: ONE PEN is one of three free of ethanol/fragrance/EO/menthol/dye · active-ingredient evidence is mostly supplier data and small vehicle-controlled studies; no product in the category has its own RCT · so we claim only "conditions scalp and hair" and plan a single-arm safety study before an RCT
Patchy loss, sudden heavy shedding, an itchy, red, sore or broken scalp, shedding with other symptoms such as weight loss or fatigue — or 9–12 months of use with no change. See a hair and scalp specialist.
Red flags: alopecia areata pattern, scarring alopecia signs (erythema, scale, pain, pustules), rapid diffuse shedding, systemic symptoms · Work-up: CBC, ferritin, TSH, vitamin D, zinc; trichoscopy; biopsy if scarring suspected · Androgenetic alopecia needs evidence-based medical treatment; supplements and cosmetics are not a substitute
Hi, I’m Hari ✨ Ask me about hair, scalp, ingredients or how to use U-TURN and ONE PEN. I answer from the real product data, and if I’m not sure, I’ll pass you to the team on LINE right away.
General information from curated evidence. Not a diagnosis. · LINE @medology