Pathogenic Mechanisms And Mechanism-Directed Therapies For Androgenetic Alopecia: Current Understanding And Future Directions

This open-label study found that combining exosome therapy with microneedling significantly improved hair density and patient satisfaction for male patients with mild to moderate androgenetic alopecia, with most reporting noticeable improvements and only mild, transient side effects after 12 months.

Standardized treatment protocols are needed for children with androgenetic alopecia.

This study reviews the role of the zinc finger protein CXXC5 in cellular signaling and its implications for cancer, discussing how its dysregulation is linked to various physiological and pathological processes, as well as potential therapies targeting CXXC5.

In this study, researchers observed that red and red-orange LED light therapy stimulates nitric oxide production and decreases dihydrotestosterone synthesis in cell models, suggesting a potential mechanism for using light therapy to treat androgenetic alopecia.

In this study, human cell models of hair follicles showed that araliadiol, a plant-derived polyacetylene compound, promotes hair growth through the p38/PPAR-γ signaling pathway, suggesting its potential as a new drug candidate for alopecia treatment.

In this study, consuming a healthy, plant-based diet was associated with reduced skin inflammation and improved overall skin health, while the potential benefits of probiotics, synbiotics, and postbiotics for skin inflammation and tissue regeneration require further investigation.

This study found that a combination of probiotic strains of Lactiplantibacillus administered over 16 weeks reduced the number and density of telogen hairs in individuals with androgenic alopecia, while increasing the abundance of Lactobacillus in their gut microbiota.

The study investigated immune cell patterns around the hair follicle infundibulum in androgenetic alopecia, revealing significant differences in immune signatures between patients with AGA and control donors, specifically noting an enrichment of CD4 cells in the patient group.

In this study, higher dietary antioxidant intake was linked to a decreased risk of androgenic alopecia, while higher dietary inflammatory intake increased the risk, especially among women, although these links were influenced by metabolic syndrome presence.

This review discusses current and emerging therapies for androgenetic alopecia, emphasizing regenerative treatments and nanotechnology advancements, but it reports no new clinical results.

This study found that patients with androgenetic alopecia had thinner scalp and subcutaneous tissues, narrower and shorter hair follicles, a lower hair follicle count, and fewer color flow signals compared to healthy volunteers, as measured by 22 MHz ultrasound.

This study reviews how oxidative stress affects hair follicle development and hair growth, discusses antioxidant-based treatments for hair loss, and evaluates natural antioxidant products that promote hair growth, emphasizing the need for further research due to existing limitations.

This study investigated the effects of heat-treated Limosilactobacillus fermentum LM1020 on hair growth and reported increased hair density, improved cellular activity, and beneficial scalp microbiota changes in patients with androgenetic alopecia over 24 weeks.

This review highlighted significant properties of probiotics that can promote hair growth and reduce dandruff, offering guidance for future research to scale these findings to pilot studies.

In this study, NMN was found to reverse hair follicle atrophy, thinning, and sparsity in mice induced by DHT, and significantly decreased DHT-induced inflammation and oxidative stress in cultured human dermal papilla cells, enhancing hair growth-related markers.

In this study, a combination of 5% minoxidil lotion and 0.25% topical finasteride spray significantly increased hair density and improved photographic assessments in men with androgenetic alopecia compared to the treatments used alone, with all methods showing good tolerability.

This study found increased infiltration of specific immune cells, such as γδ T cells and CD8+ T cells, in the bald scalp of male androgenetic alopecia patients, and identified four key immune-related genes potentially involved in hair loss development through interferon-γ signaling pathways.

This study observed that in the bald scalps of male patients with androgenetic alopecia, there was a significant downregulation of the PPAR signaling pathway, suggesting reduced adipogenesis potentially influencing hair cycling processes.

In this study on male androgenetic alopecia, the researchers reported significant increases in hair count, density, and thickness with minimal side effects over 6 weeks using adipose-derived stem cell conditioned media and minoxidil, but found no significant differences between concentrated and non-concentrated treatments.

This study found that minoxidil may treat androgenetic alopecia by affecting hormonal and enzymatic pathways, identifying new targets CYP17A1 and CYP19A1 and demonstrating its inhibition of androgenic receptors.

This review analyzed the use of 5-alpha reductase inhibitors (5ARIs) for treating various dermatological conditions such as androgenetic alopecia, acne, and hirsutism, emphasizing their efficacy and safety profile.

This review discusses the genetic differences between male and female pattern hair loss and highlights the uncertainty surrounding genetic factors in female pattern hair loss, but reports no clinical results.

This review examines the efficacy of various novel treatments for androgenetic alopecia, including oral minoxidil and platelet-rich plasma, suggesting potential benefits but emphasizing the need for further high-quality clinical trials to thoroughly evaluate their effectiveness.

This study found a high discontinuation rate of topical minoxidil among patients with androgenetic alopecia, largely influenced by short treatment duration, lack of efficacy, and adverse effects.

This study identified CXXC5 as a key mediator of hair loss induced by PGD2 and DHT via suppression of the Wnt/β-catenin pathway, with implications for potential therapeutic targets.

This review summarizes biological links between aging and androgenetic alopecia, particularly focusing on cellular senescence, and discusses potential therapeutic strategies, but reports no new clinical results.

This study found that individuals with androgenetic alopecia had higher scalp microbiome diversity and more complex scalp-gut microbiome networks than those without, suggesting a link between skin-gut microorganisms and hair loss development.

This study found that microbial adenosine and biotin treatments derived from Staphylococcus epidermidis Cicaria culture may help inhibit hair loss by maintaining the hair's growth phase.

In this study, researchers identified key transcriptome changes in male androgenetic alopecia hair follicles, suggesting that HIF-1 pathway genes and Wnt pathway inhibitors could be potential therapeutic targets.

This study found that adenosine promotes hair growth by stimulating the Wnt/β-catenin pathway in cultured human dermal papilla cells through activation of the adenosine receptor.

This review analyzed 17 recent clinical trials on platelet-rich plasma for androgenetic alopecia but reports no new clinical results; the authors seek a consensus on optimal PRP use.

This study found that mitochondrial dysfunction and higher oxidative stress in balding dermal papilla cells may contribute to androgenetic alopecia, with antioxidants potentially improving metabolite uptake.

This review discusses treatment options for androgenetic alopecia, highlighting the need for personalized, evidence-based approaches but reports no new clinical results.

This study found that androgenetic alopecia patients had significantly lower serum levels of paraoxonase 1, which correlated with disease severity and suggests a role of oxidative stress in its pathogenesis.

This study suggests that both the sebum composition and microbial imbalance on the scalp may play a role in the development of androgenetic alopecia among Japanese males.

This study demonstrated that B-mode ultrasound and shear-wave elastography could differentiate individuals at risk of developing androgenetic alopecia from healthy individuals by assessing cranial subcutaneous tissue thickness and epidermis-dermis stiffness.

This study observed that inflammation in androgenetic alopecia samples was similar to alopecia areata controls, but infundibular and isthmic inflammation were significantly more common in androgenetic alopecia cases.

This review examines the life cycle, biomarkers, and functions of hair follicle stem cells, emphasizing their role in hair loss therapy and other skin and hair disorders, but reports no new clinical results.

This commentary reviews potential dietary and mineral influences on androgenetic alopecia and suggests considering a diet low in cholesterol and glycaemic index with improved glucose control and magnesium fortification, without new clinical results.

This study reported that while topical minoxidil exhibits hair regrowth in androgenetic alopecia, oral minoxidil 5 mg/day was more effective than topical forms after six months, with low doses also potentially effective for women and other hair loss types.

This study observed that adding low-level light therapy with the GentleWaves® device to Minoxidil significantly boosted hair regrowth in men with androgenetic alopecia by reducing scalp inflammation.

This study found that while both cetirizine 1% and minoxidil 5% increased hair density in men with androgenetic alopecia, minoxidil showed a significantly higher improvement, and both treatments lost effectiveness after 8 weeks without use; cetirizine was well-tolerated with no significant adverse reactions.

In this overview, the authors note that both pharmacologic and nonpharmacologic treatments are effective for pattern hair loss, emphasizing early detection and intervention to maintain hair.

This study found that increased levels of PGD2 and prostacyclin and decreased levels of PGE2 and PGF2α were associated with baldness in androgenetic alopecia, suggesting potential targets for treatment.

This study found that dihydrotestosterone induced hair loss and changes in hair morphology in male C57BL/6 mice, effects that could be partially reversed by the AR antagonist bicalutamide.

This study demonstrates that dermal white adipose tissue regulates human hair growth and pigmentation through hepatocyte growth factor secretion, highlighting potential therapeutic targets for hair-related disorders.

This perspective highlights the role of inflammation in male and female pattern hair loss and its implications for developing future therapeutic options.

This review suggests that low-level light therapy can promote hair growth in patients with androgenetic alopecia, but more research is needed to standardize treatment parameters and assess long-term safety and efficacy.

This study found that patients with androgenetic alopecia had increased oxidative stress and microinflammation, contributing to hair loss, due to elevated levels of specific serum biomarkers compared to controls.

This study suggests that Lindera strychnifolia root extract may help restore a healthy microbial balance on the scalp in men with androgenetic alopecia after 83 days of treatment.

This review discusses the role of Wnt/β-catenin signaling in hair follicle regeneration and highlights recent progress in developing hair loss treatments targeting this pathway, but reports no new clinical results.

This study found that scalp thickness and hair follicle depth were reduced in individuals with androgenetic alopecia, and MRI signal intensity was higher compared to those without the condition.

This study reports that patients with androgenetic alopecia had lower quality of life scores across all measured domains compared to controls, with disease severity worsening the impact, particularly socially for those under 30.

In this randomized clinical trial, the authors reported that adipose-derived stem cell constituent extract topical solution increased hair density and thickness in patients with androgenetic alopecia over 16 weeks compared to placebo.

In this study, DHT was observed to have varying effects on hair follicle growth and related protein expression depending on concentration, with the Wnt/β-catenin pathway potentially playing a significant role.

This review synthesizes current research on PPAR-γ signaling in hair follicle biology and its potential role in treating hair growth disorders like scarring alopecia and hirsutism, but reports no new clinical results.

In this study, researchers identified 32 differentially expressed genes involved in androgenetic alopecia, with down-regulated genes associated with Wnt and TGF-beta signaling and up-regulated genes linked to oxidative stress pathways.

In this study on rat dermal papilla cells, hydroxytyrosol, an antioxidant found in olive oil, was reported to protect against oxidative stress, reduce inflammation, and enhance hair growth factors, suggesting its potential to prevent hair loss.

This study found that the presence of Malassezia fungi in the scalp's hairy roots was more pronounced in individuals with androgenetic alopecia than in healthy controls, suggesting a potential link to the condition.

This study observed that hair follicles in hair loss patients had increased levels of Propionibacterium acnes, potentially linked to elevated immune response gene expression in miniaturized hair follicles.

This study found that hair thickness and density increased after treatment with human follicle mesenchymal stem cells and platelet rich plasma, associated with enhanced Wnt signaling and platelet derived growth factors.

This letter to the editor about prostaglandins in androgenetic alopecia in men and women reports no new research findings.

This review found that low-level laser therapy significantly increased hair density in adults with androgenic alopecia compared to sham treatments, with greater effects observed at lower treatment frequencies.

This study observed that dandruff in Indian women is associated with a distinct scalp microbiome, including specific bacterial and unknown Malassezia species, with implications for nutrient homeostasis and cell-host adhesion pathways.

This review discusses the use of platelet-rich plasma as a treatment for androgenetic alopecia and highlights the need for standardized protocols, reporting no new clinical results.

This review found that existing studies on adipose tissue for scarring, wound healing, and hair growth show some positive outcomes, but the evidence is insufficient to change current dermatological practices.

This study suggests that minoxidil may enhance hair growth by stimulating adipose-derived stem cell motility and growth factor secretion, promoting dermal papilla cell proliferation and accelerating anagen induction.

This study found that 655-nm red light with LED enhanced hair shaft elongation and reduced catagen transition in human hair follicles in vitro by activating the Wnt/ß-catenin signaling pathway.

This study found that prostaglandin D2 promotes androgen receptor and AKT signaling in human dermal papilla cells through the DP2 receptor, potentially contributing to androgenetic alopecia.

This study found that millimolar concentrations of minoxidil in the skin induced VEGF production through HIF-1 stabilization by inhibiting PHD-2, implying a molecular mechanism for hair growth promotion.

In this study, platelet-rich plasma injections in mice promoted hair growth and angiogenesis compared to control, as evidenced by longer hair lengths and increased vessel formation.

This study found that inhibiting the interaction between CXXC5 and Dishevelled could stimulate hair regrowth in mouse models by enhancing WNT/β-catenin signaling, suggesting a potential therapeutic strategy for hair loss involving compounds that block this interaction, such as interfering short peptides.

This study found that LED light irradiation induced proliferation and migration of human outer root sheath cells, potentially through the stimulation of the Wnt/β-catenin and ERK signaling pathways.

In this study, PGD2 was shown to increase testosterone production in human keratinocytes through reactive oxygen species, suggesting potential benefits of antioxidants like N-acetyl-cysteine for AGA patients.

This study suggests that the interaction between CXXC5 and Dishevelled is a potential target for promoting hair regrowth and hair follicle formation, offering a new approach to treat hair loss.

This study found that low-level laser treatment may promote hair regrowth in mice by activating the Wnt10b/ß-catenin pathway and inducing the anagen phase of hair follicles.

This systematic review and meta-analysis found that minoxidil, finasteride, and low-level laser light therapy significantly improve hair growth in men with androgenetic alopecia, while minoxidil is also effective for women, compared to placebo.

In this study, patients with androgenetic alopecia showed significantly decreased antioxidant activity and increased oxidative stress markers, suggesting a role for oxidative stress in the condition.

In this study, researchers used genetic data from over 52,000 men to identify over 250 genetic loci associated with severe hair loss and developed a predictive algorithm for determining hair loss risk.

In this study, researchers found that the prevalence of androgenetic alopecia was higher in their sample compared to other studies in Asian and Caucasian populations, and it was linked with age-related severity.

This study suggests that LED light may promote the proliferation of human dermal papilla cells through the activation of specific signaling pathways.

This study found increased oxidative stress in younger male patients with early-onset androgenetic alopecia compared to healthy peers, suggesting a potential role for antioxidants in their treatment.

Minoxidil is the only FDA-approved topical drug for treating male or female pattern hair loss, and other medications like finasteride and dutasteride can also increase hair growth.

This study found that androgen receptor activation in adult mouse skin reduces β-catenin-induced hair follicle growth and sebaceous gland conversion, highlighting its role in stem cell fate decisions.

This study suggests that oxidative stress may contribute to androgenetic alopecia by inducing premature senescence and secretion of hair growth inhibitors in dermal papilla cells from balding scalp.

This study found that in mice, epidermal Wnt/β-catenin signaling influences adipocyte differentiation and hair growth, suggesting its critical role in synchronizing adipogenesis with the hair growth cycle.

This review discusses the potential mechanisms and evidence supporting low-level laser therapy for stimulating hair growth in men and women, while noting its safety and effectiveness but needing further study on specific parameters.

This review describes minoxidil's hair regrowth mechanism and discusses dermatological applications, but reports no new clinical results, emphasizing the need for regular use and addressing allergic reactions.

PGD2 stops hair growth and is higher in bald men with AGA.

This study found that androgens inhibit hair follicle stem cell differentiation by disrupting the Wnt signalling pathway in dermal papilla cells, but Wnt activation can restore differentiation.

This study found that intradermal adipocyte lineage cells in mice are necessary and sufficient to activate follicular stem cells, highlighting their role in regulating skin stem cell activity.

This study found that 94% of healthy men reported low libido and 92% reported erectile dysfunction as persistent sexual side effects after using finasteride for male pattern hair loss, with these effects lasting on average 40 months post-discontinuation.

This study found that topical minoxidil modestly extended the anagen phase in mice by activating β-catenin activity in dermal papilla cells.

This study found that increased expression of type II 5α-reductase, androgen receptors, and Hic-5/ARA55 in dermal papilla cells upregulates androgen sensitivity, playing a key role in androgenetic alopecia pathogenesis.

This review discusses the paracrine effects of adipose tissue-derived stem cells on surrounding cells and tissues, noting their potential therapeutic benefits, but reports no new clinical results.

This study found that human hair follicles express ATP-sensitive potassium channels, suggesting that minoxidil acts on these channels and that drugs targeting them may treat hair disorders.

This article discusses treatment options for androgenetic alopecia, noting that medical interventions like finasteride and minoxidil can halt and partially reverse hair loss in mild to moderate cases, especially when combined with surgery.

This study found that PGF2alpha analogues and PGE2 stimulated hair follicle activity in mice, with PGF2alpha analogues also linked to potential side effects like poliosis when used as eye treatments.

This paper discusses key mechanisms of androgen metabolism in androgenetic alopecia and reports the effectiveness of treatments like oral finasteride and topical minoxidil, highlighting the limited success rate due to factors like follicular inflammation.

Minoxidil boosts hair growth by targeting adenosine and possibly sulfonylurea receptor 2B.

This review discusses the relationship between perceived stress and hair loss or graying, exploring hair follicles as a model system but reports no new clinical results.

This study introduces the concept of teloptosis, which influences hair shedding during the telogen phase and affects hair density, highlighting that early or delayed teloptosis has noticeable effects.

This article discusses the treatment of androgenetic alopecia and alopecia areata with finasteride and minoxidil but reports no new clinical results.

In male pattern hair loss, this study found that finasteride 1 mg daily significantly slowed hair loss and increased hair growth over two years compared to placebo.

This study found that minoxidil significantly increases VEGF mRNA and protein expression in dermal papilla cells, suggesting a role in enhancing hair follicle vascularization in androgenetic alopecia.

This study found that dermal papilla cells from balding scalp hair follicles have significantly higher levels of androgen receptors than those from non-balding follicles, supporting their in vivo androgen response.

This study found that 2% ketoconazole shampoo improved hair density and anagen follicle proportion in androgenic alopecia similarly to minoxidil treatment, suggesting a potential role for Malassezia in inflammation.

This study suggests that minoxidil activates PGHS-1, which may explain its hair growth-stimulating effects and could aid in designing more potent hair growth-promoting drugs.

In this study, 5 mg of finasteride per day significantly improved urinary symptoms and reduced prostate volume in men with benign prostatic hyperplasia, but increased the risk of sexual dysfunction.

This study found that both 2% and 3% minoxidil resulted in a significant increase in hair counts for participants with androgenetic alopecia over 12 months.

Minoxidil increases blood flow in balding scalps, possibly reversing hair loss.