Managing Accelerated Male-Pattern Hair Loss on Testosterone Cypionate: The HealthRX.com Step-by-Step Protocol

Does testosterone cypionate cause male-pattern hair loss?

The Depo-Testosterone prescribing information lists male pattern baldness in its adverse reactions section, next to hirsutism, seborrhea and acne [1]. The label lists these skin reactions without incidence figures [1].

The mechanism runs through DHT. In many tissues the activity of testosterone appears to depend on its reduction to dihydrotestosterone [1], and 5-alpha reductase carries out that conversion: normally up to about 10% of the body's testosterone is converted to DHT [2]. DHT stays bound to the androgen receptor longer than testosterone does, roughly 53 minutes compared with 35 in the review that tabulated it, and excess DHT miniaturizes hair follicles, shortening the anagen (growth) phase and lengthening the telogen (resting) phase [2].

Male-pattern hair loss follows a recognizable course: bitemporal recession of the frontal hairline first, followed by diffuse thinning at the vertex, and the condition tends to worsen over time [3]. Androgenetic alopecia affects up to 80% of men at some point in life [3]. A 2017 review of testosterone therapy in transgender men lists alopecia among the undesired effects and notes that alopecia continues to develop beyond the first year of treatment [6].

What the treatment evidence covers

A meta-analysis of randomized controlled trials in men with androgenetic alopecia pooled studies of 5% minoxidil, 2% minoxidil, 1 mg finasteride and low-level laser therapy; every one of those treatments was superior to placebo for hair density, thickness or growth [4]. Those trials enrolled men with male-pattern hair loss, and the outcomes were hair measures and patient or investigator assessments, not hormone levels on testosterone replacement [4].

How the pattern is confirmed

Scalp dermoscopy is used routinely in androgenetic alopecia. It facilitates the diagnosis and differential diagnosis with other diseases, allows severity to be staged, and allows progress and response to treatment to be monitored over time [3].

The treatments that have been tested

Topical minoxidil. In the meta-analysis, 5% minoxidil beat placebo in men, and 2% minoxidil beat placebo as well [4]. Both strengths were analyzed as separate groups of trials and each was superior to placebo [4].

Oral finasteride. The same meta-analysis found 1 mg finasteride superior to placebo in men [4]. Finasteride blocks 5-alpha reductase, and in a phase III trial oral finasteride lowered mean serum DHT by 55.6% [7].

Topical finasteride. A phase III, double-blind, double-dummy trial randomized 458 men with androgenetic alopecia to a topical finasteride spray, oral finasteride or placebo for 24 weeks; 323 completed and 446 were evaluated for safety [7]. Change in target-area hair count at week 24, the primary endpoint, was 20.2 hairs with the spray versus 6.7 with placebo (P<0.001), numerically similar to oral finasteride [7]. Mean serum DHT fell 34.5% with the spray and 55.6% with the tablet, and peak plasma finasteride concentrations were more than 100 times lower with the spray; the authors conclude there is less likelihood of systemic sexual adverse reactions related to lowered DHT with the spray [7].

Dutasteride. Dutasteride is a competitive inhibitor of both type 1 and type 2 of 5-alpha reductase, and a review of randomized, double-blind, placebo-controlled trials found it effective in androgenetic alopecia and better than finasteride in most of those studies, with comparable adverse effects [5]. Minoxidil and finasteride are the only drugs approved for the condition, so hair-loss use of dutasteride is off-label [5].

Low-level laser therapy. Laser therapy was superior to placebo in the meta-analysis, and the HairMax LaserComb is FDA-cleared for androgenetic alopecia [4].

Where the testosterone dose fits

The Depo-Testosterone label states that dosage is adjusted according to the patient's response and the appearance of adverse reactions, within a suggested range of 50 to 400 mg every 2 to 4 weeks, and that the half-life after intramuscular injection is about 8 days [1]. Male pattern baldness is one of the reactions on that list [1]. The label names no hair-specific dose or interval [1].