Treatment of male and female pattern hair loss with sublingual minoxidil: a retrospective case‐series of 64 patients

Clinical and preclinical approach in AGA treatment: a review of current and new therapies in the regenerative field

Androgenetic alopecia (AGA) is the most prevalent type of hair loss. Its morbility is mainly psychological although an increased incidence in melanoma has also been observed in affected subjects. Current drug based therapies and physical treatments are either unsuccessful in the long term or have relevant side effects that limit their application. Therefore, a new therapeutic approach is needed to promote regenerative enhancement alternatives. These treatment options, focused on the cellular niche restoration, could be the solution to the impact of dihydrotestosterone in the hair follicle microenvironment. In this context emerging regenerative therapies such as Platelet-rich plasma or Platelet-rich fibrine as well as hair follicle stem cells and mesenchymal stem cell based therapies and their derivatives (conditioned medium CM or exoxomes) are highlighting in the evolving landscape of hair restoration. Nanotechnology is also leading the way in AGA treatment through the design of bioinks and nanobiomaterials whose structures are being configuring in a huge range of cases by means of 3D bioprinting. Due to the increasing number and the rapid creation of new advanced therapies alternatives in the AGA field, an extended review of the current state of art is needed. In addition this review provides a general insight in current and emerging AGA therapies which is intented to be a guidance for researchers highlighting the cutting edge treatments which are recently gaining ground.

Androgenetic alopecia in transgender and gender diverse populations: A review of therapeutics

Androgenetic alopecia (AGA) management is a significant clinical and therapeutic challenge for transgender and gender-diverse (TGD) patients. Although gender-affirming hormone therapies affect hair growth, there is little research about AGA in TGD populations. After reviewing the literature on approved treatments, off-label medication usages, and procedures for treating AGA, we present treatment options for AGA in TGD patients. The first-line treatments for any TGD patient include topical minoxidil 5% applied to the scalp once or twice daily, finasteride 1 mg oral daily, and/or low-level laser light therapy. Spironolactone 200 mg daily is also first-line for transfeminine patients. Second-line options include daily oral minoxidil dosed at 1.25 or 2.5 mg for transfeminine and transmasculine patients, respectively. Topical finasteride 0.25% monotherapy or in combination with minoxidil 2% solution are second-line options for transmasculine and transfeminine patients, respectively. Other second-line treatments for any TGD patient include oral dutasteride 0.5 mg daily, platelet-rich plasma, or hair restoration procedures. After 6-12 months of treatment, AGA severity and treatment progress should be assessed via scales not based on sex; eg, the Basic and Specific Classification or the Bouhanna scales. Dermatologists should coordinate care with the patient's primary gender-affirming clinician(s) so that shared knowledge of all medications exists across the care team.

Systemic minoxidil for hair disorders in pediatric patients: a safety and tolerability review

Topical minoxidil has been used for many years to treat adult alopecia, and there is growing evidence supporting the off-label use of low-dose oral minoxidil (LDOM). However, there is little data on its use in pediatrics, and there are no recommended treatment guidelines. Adverse events are of particular concern in this population. We retrospectively reviewed the medical records of 63 patients aged between 0 and 12 years from a specialist hair clinic who were treated with LDOM or sublingual minoxidil (SM) to evaluate its safety and tolerability. LDOM and SM were generally well-tolerated, with mild hypertrichosis being the most commonly reported adverse event. Further large-scale studies are warranted to determine the efficacy and optimum dosage of systemic minoxidil for alopecia in the pediatric population.

Alpinetin promotes hair regeneration via activating hair follicle stem cells

Background

Alopecia affects millions of individuals globally, with hair loss becoming more common among young people.  Various traditional Chinese medicines (TCM) have been used clinically for treating alopecia, however, the effective compounds and underlying mechanism are less known. We sought to investigate the effect of Alpinetin (AP), a compound extracted from Fabaceae and Zingiberaceae herbs, in hair regeneration.

Methods

Animal model for hair regeneration was mimicked by depilation in C57BL/6J mice. The mice were then topically treated with 3 mg/ml AP, minoxidil as positive control (PC), or solvent ethanol as vehicle control (VC) on the dorsal skin. Skin color changes which reflected the hair growth stages were monitored and pictured, along with H&E staining and hair shaft length measurement. RNA-seq analysis combined with immunofluorescence staining and qPCR analysis were used for mechanism study. Meanwhile, Gli1^CreERT2; R26R^tdTomato and Lgr5^{EGFP−CreERT2}; R26R^tdTomato transgenic mice were used to monitor the activation and proliferation of Gli1+ and Lgr5+ HFSCs after treatment. Furthermore, the toxicity of AP was tested in keratinocytes and fibroblasts from both human and mouse skin to assess the safety.

Results

When compared to minoxidil-treated and vehicle-treated control mice, topical application of AP promoted anagen initiation and delayed catagen entry, resulting in a longer anagen phase and hair shaft length. Mechanistically, RNA-seq analysis combined with immunofluorescence staining of Lef1 suggested that Lgr5+ HFSCs in lower bulge were activated by AP via Wnt signaling. Other HFSCs, including K15+, Lef1+, and Gli1+ cells, were also promoted into proliferating upon AP treatment. In addition, AP inhibited cleaved caspase 3-dependent apoptosis at the late anagen stage to postpone regression of hair follicles. More importantly, AP showed no cytotoxicity in keratinocytes and fibroblasts from both human and mouse skin.

Conclusion

This study clarified the effect of AP in promoting hair regeneration by activating HFSCs via Wnt signaling. Our findings may contribute to the development of a new generation of pilatory that is more efficient and less cytotoxic for treating alopecia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00619-2.

Minoxidil: a comprehensive review

Topical minoxidil (5% foam, 5% solution, and 2% solution) is FDA-approved for androgenetic alopecia (AGA) in men and women.Mechanism of action: Minoxidil acts through multiple pathways (vasodilator, anti-inflammatory agent, inducer of the Wnt/β-catenin signaling pathway, an antiandrogen), and may also affect the length of the anagen and telogen phases.Pharmacokinetics: Approximately 1.4% of topical minoxidil is absorbed through the skin. Minoxidil is a prodrug that is metabolized by follicular sulfotransferase to minoxidil sulfate (active form). Those with higher sulfotransferase activity may respond better than patients with lower sulfotransferase activity.Clinical efficacy (topical minoxidil): In a five-year study, 2% minoxidil exhibited peak hair growth in males at year one with a decline in subsequent years. Topical minoxidil causes hair regrowth in both frontotemporal and vertex areas. The 5% solution and foam were not significantly different in efficacy from the 2% solution.Oral and Sublingual minoxidil (not FDA approved; off-label): After 6 months of administration, minoxidil 5 mg/day was significantly more effective than topical 5% and 2% in male AGA. Low-dose 0.5-5 mg/day may also be safe and effective for female pattern hair loss and chronic telogen effluvium. Sublingual minoxidil may be safe and effective in male and female pattern hair loss.

Female pattern hair loss: A comprehensive review

Female pattern hair loss is a common form of hair loss in women that increases in incidence with age. The etiology is unknown with numerous factors identified that influence its onset. Female pattern hair loss may be viewed as a marker for an increased risk of cardiovascular and metabolic disease. New treatments include microneedling, low-level laser therapy, and autologous fat transfer. This article focuses on the pathophysiology, diagnosis, systemic associations, and current treatments for female pattern hair loss, which is the most common cause of alopecia in women.

Oral minoxidil treatment for hair loss: A review of efficacy and safety

BACKGROUND

Although topical minoxidil is an effective treatment option for hair loss, many patients are poorly compliant because of the necessity to apply the medication twice a day, undesirable hair texture, and scalp irritation.

OBJECTIVE

In recent years, oral minoxidil at low dose has been proposed as a safe alternative. This study reviewed articles in which oral minoxidil was used to treat hair loss to determine its efficacy and safety as an alternative to topical minoxidil.

METHODS

PubMed searches were performed to identify articles discussing oral minoxidil as the primary form of treatment for hair loss published up to April 2020.

RESULTS

A total of 17 studies with 634 patients were found discussing the use of oral minoxidil as the primary treatment modality for hair loss. Androgenetic alopecia was the most studied condition, but other conditions included telogen effluvium, lichen planopilaris, loose anagen hair syndrome, monilethrix, alopecia areata, and permanent chemotherapy-induced alopecia.

LIMITATIONS

Larger randomized studies comparing the efficacy/safety of different doses with standardized objective measurements will be needed to clarify the best treatment protocol.

CONCLUSION

Oral minoxidil was found to be an effective and well-tolerated treatment alternative for healthy patients having difficulty with topical formulations.