Peer-reviewed studies on hair loss, scalp science, and new treatments. Read closely and reported in plain language.
Roughly half the people who use 5% topical minoxidil don’t respond. They aren’t using it wrong. They’re missing the enzyme. The peer-reviewed evidence on the plucked-hair sulfotransferase assay, the tretinoin priming protocol, the SULT1A1 booster trials, and the 2024 oral-minoxidil paradox that flips the rule on its head.
Minoxidil, finasteride, dutasteride, spironolactone. What the latest evidence actually shows.
A 0.25% topical spray drops scalp DHT with serum concentrations more than 100 times lower than the oral 1 mg tablet. The 2022 Etincelle Phase III, the 2025 Chinese Phase III, the female pattern data, and the April 2025 FDA alert most clients have never heard.
No. 021Dutasteride blocks both type I and type II 5-alpha reductase and suppresses 98% of serum DHT. A Phase II showed topical dutasteride producing +75.5 hairs/cm² with zero adverse events. The evidence, the delivery routes, and what practitioners need to know.
No. 022A 2025 placebo-controlled pilot RCT, a head-to-head against bicalutamide in 204 women, and a 2025 JAAD review. The mechanism, the updated evidence, and patient selection.
No. 018A 2025 meta-analysis of 27 studies and 2,933 patients. An international Delphi consensus from 43 specialists. Head-to-head data with topical formulations.
No. 002Clascoterone, GT20029, and PP405 represent three entirely different mechanisms of action, and they’re all in clinical trials right now.
When the follicle can’t come back. The conditions, the windows, the missed diagnoses.
LPP is a lymphocytic primary scarring alopecia driven by a Th1/IFN-γ attack on the follicular bulge. The Chiang 2010 paper introduced the LPPAI. Hydroxychloroquine produces significant improvement in 69% of patients at 6 months. The Karnik PPAR-γ mechanism, the Cho mycophenolate evidence, and the emerging JAK-inhibitor case series. What it takes to catch LPP before the follicles are gone.
No. 026The 2019 GWAS at HLA-B*07:02 and CYP1B1, the contested sunscreen hypothesis, and the 2024 finasteride-vs-hydroxychloroquine RCT.
No. 024The 2019 NEJM paper on PADI3. The Hopkins fibroproliferative pathway. A 2023 case series on topical metformin 10%.
No. 010The histopathology of LPP, FFA, CCCA, and DLE. Why the sebaceous gland goes first.
No. 012Early disease is reversible. Late disease is not. The line is drawn by perifollicular fibrosis, and it’s often crossed before anyone notices.
Hair loss never starts at the scalp. Hormones, gut, stress, drugs, nutrients.
A 2025 JAAD Reviews paper maps the HPA axis and cytokine cascade. A 2024 biochemical study of 180 women challenges the routine micronutrient narrative. A systematic review questions whether chronic TE is even a distinct diagnosis.
No. 025Alopecia appeared in STEP 1 and SURMOUNT-1 at 3.0% and 5.7% versus 1.0–1.5% placebo. A 2024 FAERS analysis confirmed the signal. Mechanism: telogen effluvium from rapid loss, with possible direct pharmacology.
No. 013Thyroid, cortisol, estrogen, and PCOS each disrupt the hair cycle through completely different mechanisms.
No. 006Alopecia patients show distinct gut microbiome profiles. New 2025 studies map the path from dysbiosis to follicle immune privilege collapse.
No. 004A 2025 study of 100 women found 65% of TE patients had low ferritin even within normal lab ranges.
No. 001A 2025 multi-kingdom sequencing study proves that scalp microbiome dysbiosis is a measurable, predictable component of androgenetic alopecia. The disruption happens across the entire scalp, not just where you see thinning.
No. 005A 2025 cross-sectional study of 520 patients found 66% infested with Demodex, with a direct correlation between mite density and hair loss severity. How they destroy follicles, and what actually kills them.
Photobiomodulation, microneedling, PRP, exosomes, plasma, JAK. The evidence behind the new modalities.
The only FDA-cleared device-based treatment for pattern hair loss. New mechanistic data on Wnt/β-catenin activation in dermal papilla cells, plus the first formal expert consensus.
No. 019From anecdotal add-on to the most-studied adjunctive hair loss treatment in dermatology. The Wnt/β-catenin mechanism, gender-specific findings, and the protocol standardization gap.
No. 01443 RCTs. 1,877 participants. A 2025 systematic review confirms efficacy comparable to topical minoxidil for AGA.
No. 011The fastest-growing conversation in regenerative hair medicine, and one of the most commercially overhyped. The data, the FDA warnings, the regulatory reality.
No. 009CAP activates Wnt/β-catenin signaling in dermal papilla cells. A 2025 JAAD study documents hair growth in humans.
No. 017Baricitinib, ritlecitinib, and deuruxolitinib are now FDA-approved for severe alopecia areata, all targeting the IFN-γ/JAK-STAT positive feedback loop that collapses hair follicle immune privilege. Phase 3 trials in thousands of patients, 24-month long-term extension data, Bayesian network meta-analyses comparing efficacy, and the relapse reality when treatment stops.
The hair cycle clock, pediatric loss, gray reversal, chemo, AI diagnostics.
A 2025 Nature Communications study identified H2AK119ub as a chromatin-level switch linking FGF signaling to sustained HFSC quiescence. The molecular timer behind anagen, catagen, and telogen.
No. 015Tinea capitis, alopecia areata, telogen effluvium. Pediatric hair loss requires distinct diagnostic logic. UVFD, the new ritlecitinib approval, what practitioners need to know.
No. 008Melanocyte stem cells get stuck rather than die. A landmark 2023 Nature study, plus 2024–2025 work on luteolin and exosomes.
No. 007A meta-analysis of 2,179 patients reveals more than 40% experience permanent partial alopecia. Stem cell damage, scalp cooling, post-chemo recovery.
No. 003New research on AI-powered trichoscopy and non-invasive scalp detection is changing how we assess severity and predict outcomes.
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