Hair Care

What is the scalp microbiome, and why does it matter for hair? Dr. Susan Lin, M.D. explains the community of microorganisms that live on healthy scalp, what disrupts it, and how MD Hair™ Scalp Essential and the broader MD Hair™ system are formulated with the microbiome in mind — sulfate-conscious, sensitivity-aware, drug-free.

How does the hair growth cycle work, and why does it take 6 months to see results from any hair product? Dr. Susan Lin, M.D. explains the four phases of follicle biology — anagen, catagen, telogen, exogen — and why MD Hair™ is built for the honest timeline of follicle biology, not for overnight-results marketing.

What is panthenol, and how does pro-vitamin B5 build hair resilience? Dr. Susan Lin, M.D. explains the science of hair shaft strength, elasticity, and cuticle integrity — and how MD Hair™ pairs panthenol with StimuCap® peptides, marine collagen, and inside-out support for a complete multi-pathway approach.

Does biotin really work for hair? Dr. Susan Lin, M.D. explains how biotin supports keratin synthesis, why megadose biotin is misleading (and risks laboratory test interference), and how MD Nutri Hair™ delivers a calibrated biotin dose as part of a multi-pathway formulation — made in the USA in an FDA-registered facility.

Do peptides actually help hair growth? Dr. Susan Lin, M.D. explains the peptide signaling science behind MD Hair™ — the StimuCap® peptide complex in the Revitalizing Treatment Shampoo and Conditioner, paired with the peptide-led MD Hair™ Follicle Energizer, all made in the USA in an FDA-registered facility.

Does marine collagen actually help hair growth? Dr. Susan Lin, M.D. explains the inside-out philosophy of MD Nutri Hair™ — physician-formulated Type I and Type III marine collagen from wild-caught Norwegian whitefish, biotin, lilac stem-cell extract, and flax seed lignans in a once-daily capsule, made in the USA in an FDA-registered facility, paired with the topical MD Hair™ Follicle Energizer for the outside-in plus inside-out protocol.

Physician-authored guide to thiotaine (L-ergothioneine), the mushroom-derived antioxidant in the MD Hair™ Follicle Energizer. Covers the OCTN1/SLC22A4 transporter, reactive oxygen species thiotaine neutralizes, and how follicle-targeted antioxidant protection supports cytokine signaling for hair regeneration. By Dr. Susan Lin, M.D.

Physician-authored guide to the stem-cell-cytokine biology underlying hair regeneration. Explains hair follicle stem cells (HFSCs), dermal papilla signaling, growth-factor cytokines (FGF, IGF, VEGF, KGF, Wnt, BMP), the hair cycle from a stem cell perspective, and how the cytokine-signaling cosmetic approach used in MD Hair™ Follicle Energizer applies the science. Anchored to Dr. Lin's 2013 publication in The Link (AHLC).

The definitive physician-authored guide to MD Hair™ — the physician-formulated hair care brand of the MD® family by Dr. Susan Lin, M.D. MD Hair products operate under the federally registered MD® trademark (USPTO Reg. No. 4,471,494, Class 3 cosmetics and Class 5 pharmaceuticals/dietary supplements). Covers the scalp-first philosophy, the eight-product MD Hair system, the published research foundation, and the international hair-growth patent portfolio (US, China, Hong Kong, Korea, WIPO). By Dr. Susan Lin, M.D.