Science Journalist & Patient Advocate
Liam Foster
Liam Foster began losing his hair at 22. That experience sent him on a decade-long journey through clinical trials, experimental treatments, and conversations with leading scientists worldwide. He now writes about the science of hair loss with the urgency of someone who has lived it.
Articles by Liam
Hair Follicle Cloning Is Closer Than You Think, And Further Than You Hope
Stemson Therapeutics completed its first human safety study in 2025. The science works in mice. The gap between a mouse follicle and a human scalp is, unfortunately, significant.
Liam Foster
17 days ago
Prostaglandin D2: The Hidden Brake on Hair Growth That Scientists Have Known About Since 2012
A decade ago, a landmark study identified PGD2 as a potent inhibitor of hair follicle growth, elevated in bald scalp. Why is no approved treatment targeting it yet?
Liam Foster
19 days ago
Verteporfin Is Rewriting What We Thought We Knew About Hair Transplant Scars
A repurposed ophthalmology drug is showing an unexpected ability to suppress scar formation in hair transplant wounds, potentially enabling follicle regeneration rather than simple transfer.
Liam Foster
22 days ago
HairClone Is Banking Follicles Now So You Can Restore Hair Later, But When Is 'Later'?
The UK company has been collecting follicle samples since 2020. They're betting that cell therapy technology will mature in time to use what they're storing. I spent three months trying to work out whether that bet is rational.
Liam Foster
24 days ago
Oral Minoxidil at 1.25mg Is Working Differently to What Anyone Expected
Low-dose oral minoxidil has become one of the most prescribed off-label treatments in dermatology. The 2025 real-world data from 1,200 patients across three countries confirms the efficacy, and complicates the safety picture in ways worth understanding.
Liam Foster
26 days ago
Follica's Skin Disruption Protocol Is the Most Overlooked Hair Loss Treatment in Development
The idea that you can create new hair follicles by wounding the scalp sounds implausible. The science behind Follica's approach says otherwise, and their Phase 3 trial data has finally been submitted to the FDA.
Liam Foster
28 days ago
Your Scalp Has a Microbiome. It Might Be Contributing to Your Hair Loss.
Research into the scalp microbiome is revealing links between bacterial and fungal communities and hair loss that go beyond simple dandruff. The therapeutic implications are only beginning to be explored.
Liam Foster
30 days ago
Low-Level Laser Therapy for Hair Loss: What the 2025 Evidence Actually Shows
LLLT devices have been FDA-cleared for hair loss since 2007. Eighteen years later, a Cochrane-style systematic review has assembled the most rigorous evidence yet, and the picture is more nuanced than the device manufacturers suggest.
Liam Foster
about 1 month ago
Scientists Have Mapped the Mechanism Behind Chronic Telogen Effluvium, IL-33 Is the Key
Telogen effluvium, the diffuse hair shedding that follows stress, illness, or hormonal shifts, has lacked a clear molecular explanation for chronic cases. New research points to IL-33 and the innate immune system.
Liam Foster
about 1 month ago
COVID-19 Hair Loss Three Years On: What the Long-Term Data Tells Us
Post-COVID telogen effluvium was one of the most widely reported symptoms of long COVID. Three years on, research from 40,000 patients answers the questions that early reports couldn't: how many recover, and who doesn't?
Liam Foster
about 1 month ago
Finasteride at 10 Years: The Most Important Long-Term Safety Study Yet Published
A prospective 10-year study of finasteride 1mg for androgenetic alopecia, the longest rigorous follow-up ever conducted, has data on efficacy maintenance, sexual side effects, and cardiovascular outcomes that every user should know.
Liam Foster
about 1 month ago
Biotin and Hair Loss: What the Evidence Actually Shows (It's Not What the Supplement Industry Tells You)
Biotin supplements for hair loss generate over $2 billion in annual sales. The evidence base for this billion-dollar market is thinner than most users suspect, and the cases where biotin genuinely helps are narrower than marketing implies.
Liam Foster
about 1 month ago
Topical Finasteride Is Safer Than Oral, But the Pharmacokinetic Data Tells a More Complicated Story
The pitch for topical finasteride is straightforward: get the hair regrowth without the systemic side effects. The pharmacokinetic data shows the picture is more nuanced than the marketing suggests.
Liam Foster
about 2 months ago
Semaglutide and Hair Loss: What 18 Months of Real-World Data Shows
GLP-1 receptor agonists like semaglutide produce rapid weight loss, and a small but consistent fraction of users report telogen effluvium. The mechanism is now clearer.
Liam Foster
about 2 months ago
Frontal Fibrosing Alopecia: The Mysterious Epidemic Affecting Postmenopausal Women
Frontal fibrosing alopecia was a rare diagnosis until the 1990s. Now it affects an estimated 1–2% of postmenopausal women, and we still don't know exactly why.
Liam Foster
2 months ago
Saw Palmetto for Hair Loss: A Mechanism Without Clinical Evidence
Saw palmetto extract is in dozens of hair loss supplements. The 5-alpha reductase inhibition is real in vitro. The clinical evidence remains stubbornly thin.
Liam Foster
2 months ago
Vitamin D Deficiency and Hair Loss: The Causal Question Is Still Open
Vitamin D receptors are expressed on hair follicle cells, and deficient patients often have hair loss. Whether supplementation reverses the loss is a more complicated question.
Liam Foster
3 months ago
Postpartum Hair Loss: Timing, Severity, and When to Worry
Postpartum hair shedding affects roughly half of new mothers. The timing is predictable, the cause is well understood, but a meaningful minority of women have persistent effects.
Liam Foster
3 months ago
Pumpkin Seed Oil for Hair Loss: A Surprising Trial With Replication Pending
A 2014 Korean trial reported substantial hair count improvements from oral pumpkin seed oil. The methodology was unusual and replication is overdue, but the mechanism is plausible.
Liam Foster
3 months ago
Scalp Micropigmentation: When the Best Hair Loss Treatment Isn't About Hair
Scalp micropigmentation creates the appearance of a closely shaved head through pointillist pigment deposits. For some patients it produces better cosmetic outcomes than any hair-growing approach.
Liam Foster
4 months ago
Genetic Testing for Hair Loss: What 23andMe and Polygenic Scores Actually Predict
Direct-to-consumer genetic tests report male pattern hair loss risk. The science behind those reports is more complicated, and less predictive, than the marketing suggests.
Liam Foster
4 months ago
Compounded Topical Formulations: The Pharmacy Workaround That Has Quietly Reshaped Treatment
Compounding pharmacies have become a significant force in hair loss treatment, producing custom topical formulations that combine multiple active ingredients in single products.
Liam Foster
4 months ago
Hair Loss in Postmenopausal Women: Distinct Patterns Need Distinct Treatment
Female pattern hair loss in postmenopausal women has distinct features compared to pre-menopausal cases, and treatment approaches that work pre-menopause sometimes fail after.
Liam Foster
5 months ago
Hair Fibre Concealers: Toppik, Caboki, and What Actually Works
Keratin hair fibres are the most cost-effective cosmetic treatment for mild hair loss. Different brands use different fibre materials with substantially different performance characteristics.
Liam Foster
5 months ago
Setipiprant: The PGD2 Antagonist That Almost Was
Setipiprant blocks the prostaglandin D2 receptor implicated in androgenetic alopecia. The drug had a promising mechanism and a disappointing development path. Here's what happened.
Liam Foster
5 months ago
Sulfate-Free Shampoo: Marketing Hype or Genuine Hair Health Benefit?
Sulfate-free shampoos dominate the premium hair care market with claims of gentler cleansing. The trichology evidence is more measured than the marketing language suggests.
Liam Foster
5 months ago
Hair Systems and Toppers: When Wearing Hair Makes More Sense Than Growing It
Modern hair systems are unrecognisable from the toupées of the 1980s. For patients with extensive hair loss, they offer instant, high-quality cosmetic transformation that other approaches can't match.
Liam Foster
6 months ago
Cold Cap Therapy for Chemotherapy Hair Loss: What 2025 Data Shows
Scalp cooling during chemotherapy can preserve hair for many patients. The 2025 outcomes registry of 8,400 patients defines who benefits and how much.
Liam Foster
6 months ago
Dense Packing in Hair Transplantation: How Many Grafts Per Square Centimetre?
Dense packing pushes graft density toward the natural 80–100 follicular units per cm² that healthy scalp shows. The technique improved transplant results, but pushed against survival limits.
Liam Foster
6 months ago
Carboxytherapy for Hair Loss: A Procedure With Mechanism but Limited Evidence
Carboxytherapy, subcutaneous injection of medical CO2, has been used for various dermatological indications. The hair loss application has theoretical merit but slim clinical data.
Liam Foster
7 months ago
Cyclosporine for Alopecia Areata: An Older Option Worth Revisiting
Before JAK inhibitors, cyclosporine was one of the more effective systemic options for severe alopecia areata. New protocols make it relevant again for specific clinical scenarios.
Liam Foster
7 months ago
Trichotillomania: Hair Loss From an Underrecognised Mental Health Condition
Trichotillomania, compulsive hair pulling, affects approximately 1% of adults but is underdiagnosed because patients rarely volunteer the behaviour. Treatment requires recognising it.
Liam Foster
7 months ago
Hair Loss Patterns in African Descent: CCCA and Distinct Considerations
Central centrifugal cicatricial alopecia is the most common scarring alopecia in women of African descent. It's underdiagnosed and treatment opportunities are time-limited.
Liam Foster
7 months ago
Olaplex and Bond Builders: Repair Chemistry That Actually Works
Olaplex's patented bond-rebuilding chemistry was unusual in the hair care industry, actually novel chemistry rather than reformulated standards. The clinical results justify the marketing for damaged hair.
Liam Foster
8 months ago
Rogaine Foam vs Solution: Which Formulation Actually Works Better?
Most users assume Rogaine foam and solution work identically. The pharmacokinetic data shows they don't, and the difference matters for some users.
Liam Foster
8 months ago
Online Hair Loss Telemedicine: Hims, Keeps, and Roman Compared
Telemedicine has reshaped hair loss treatment access, with three major US players competing for the same minoxidil and finasteride prescriptions. Here's how they compare.
Liam Foster
8 months ago
Topical Immunotherapy for Alopecia Areata: An Old Treatment Worth Knowing About
Diphencyprone-induced contact dermatitis on the scalp can promote hair regrowth in alopecia areata. The treatment is older than JAK inhibitors and remains useful in specific cases.
Liam Foster
8 months ago
Collagen Supplements for Hair: Marketing Disconnect From Evidence
Collagen supplements are marketed extensively for hair benefits. Hair is made of keratin, not collagen, and the evidence for any indirect benefit is thin.
Liam Foster
9 months ago
Hair Loss in Adolescents: When Pattern Hair Loss Starts Young
Androgenetic alopecia can begin in late adolescence in patients with strong genetic predisposition. Treatment timing and choice in young patients deserves specific consideration.
Liam Foster
9 months ago
Alcohol and Hair Loss: A Modest Connection With Practical Implications
Heavy alcohol consumption has multiple indirect effects on hair health. Moderate consumption probably doesn't matter, but heavy use does.
Liam Foster
9 months ago
Hair Pull Test: The Diagnostic Procedure Anyone Can Perform
The hair pull test is one of the simplest diagnostic procedures in dermatology. Performed correctly, it distinguishes active telogen effluvium from stable hair loss.
Liam Foster
10 months ago
Hair Loss in Trans Men on Testosterone: Pattern and Timing
Testosterone therapy for transmasculine patients reproduces the androgen environment that drives male pattern hair loss. Timing, pattern, and treatment considerations differ from cisgender presentations.
Liam Foster
10 months ago
Heat Styling Damage and Hair Loss: When Cosmetic Damage Becomes Clinical Concern
Daily heat styling damages the hair shaft but doesn't typically cause follicle loss. Where heat styling crosses into clinical territory is more complicated.
Liam Foster
10 months ago
Hair Transplant Repair Procedures: Fixing Bad Past Work
Patients with poor outcomes from past hair transplants, pluggy hairlines, depleted donor areas, visible scarring, have increasingly sophisticated repair options.
Liam Foster
10 months ago
Mediterranean Diet and Hair Loss: An Observational Association Worth Knowing
A 2018 case-control study reported reduced androgenetic alopecia in men following Mediterranean diet patterns. The mechanism is plausible but the evidence is observational.
Liam Foster
11 months ago
Concealer Sprays for Hair Loss: When Spray-On Coverage Makes Sense
Spray-on concealers offer immediate visual coverage of thinning areas with less effort than fibre-based products. The category has matured significantly since the early infomercial era.
Liam Foster
11 months ago
Methotrexate for Alopecia Areata: Old Drug, Specific Use Cases
Methotrexate has supporting evidence for severe alopecia areata, particularly in combination with corticosteroids. It remains a useful option in specific clinical scenarios.
Liam Foster
11 months ago
Anagen Effluvium: When Hair Loss Comes Mid-Cycle
Anagen effluvium describes hair loss from follicles in growth phase, most commonly from chemotherapy. Understanding the mechanism helps distinguish it from telogen effluvium.
Liam Foster
11 months ago
Brushing Technique and Scalp Circulation: Folklore vs Physiology
The advice to brush hair 100 strokes daily for scalp health has folklore status. The physiology supports much more modest claims.
Liam Foster
12 months ago
Maintenance After Hair Transplant: The Medical Therapy You Can't Skip
Hair transplantation moves follicles from donor to recipient areas. It does not stop ongoing native hair loss. Post-transplant medical therapy is essential for durable results.
Liam Foster
12 months ago
Hair Loss in Endurance Athletes: Energy Availability and Telogen Effluvium
Female endurance athletes with low energy availability frequently develop hair loss alongside other features of relative energy deficiency in sport (RED-S).
Liam Foster
about 1 year ago
Hair Loss From PPI Use: A Connection With Plausibility but Modest Evidence
Long-term proton pump inhibitor use has been linked to telogen effluvium in some studies. The mechanism is plausible through micronutrient absorption effects.
Liam Foster
about 1 year ago
Melatonin for Hair Loss: The Sleep Hormone With a Real but Modest Effect on Follicles
Topical melatonin sounds like wellness nonsense. The actual trial data shows a small but measurable effect on follicle density, with a coherent biological mechanism.
Liam Foster
about 1 year ago