Dihydrotestosterone (DHT) is a potent androgen, a steroid hormone that stimulates the development and maintenance of male characteristics. It is a derivative of testosterone and is the most active form of androgen in specific tissues. The question of whether DHT increases libido, or sexual desire, depends on its unique biological power and location of action. This article explains the mechanisms by which DHT influences sexual desire and explores the consequences when its production is medically altered.
The Relationship Between Testosterone and DHT
DHT is a metabolite created from testosterone. This conversion is catalyzed by the enzyme 5-alpha reductase (5-AR) in various target tissues. Approximately 5% to 10% of circulating testosterone is converted into DHT daily, yielding a powerful biological effect.
DHT is considered biologically stronger than its precursor due to its affinity for the androgen receptor (AR). DHT binds to the AR with an affinity two to three times greater than testosterone. Once bound, DHT dissociates at a much slower rate, making its signaling effect more sustained and robust. This high potency means that DHT acts as the final, most active androgen in the tissues where it is locally produced, including areas relevant to sexual function.
How DHT Specifically Impacts Sexual Desire
DHT’s impact on sexual desire is rooted in its inability to be converted into estrogen, a process known as aromatization. While testosterone can be converted into both DHT and estradiol, DHT is non-aromatizable. This ensures that its powerful binding to androgen receptors provides a direct, uninterrupted androgenic signal, particularly in the central nervous system (CNS).
The brain regions regulating sexual motivation and desire, such as the hypothalamus and the limbic system, contain a high concentration of androgen receptors. DHT’s strong and sustained binding to these CNS receptors translates directly into heightened sexual motivation and desire. The direct androgenic action of DHT is critical, distinguishing its specific role from the broader effects of testosterone.
Clinical Relevance of DHT Blockade on Libido
The link between DHT and sexual desire is clear when DHT production is intentionally reduced using medication. 5-alpha reductase inhibitors (5-ARIs), including finasteride and dutasteride, are commonly prescribed to treat benign prostatic hyperplasia (BPH) and male pattern hair loss. These medications block the 5-AR enzyme, preventing the conversion of testosterone into DHT.
Since DHT is influential in stimulating sexual desire, blocking its production often results in decreased libido as a side effect. Clinical trials show an increased risk of developing hypoactive sexual desire and erectile dysfunction in men taking 5-ARIs compared to a placebo. The prevalence of decreased libido reported in clinical trials is typically in the range of 2% to 5% of patients.
The reduction in DHT disrupts the androgen signaling pathway in the CNS that drives sexual motivation, leading to a measurable decrease in desire for some individuals. The response to 5-ARI treatment is highly variable; while some men experience no sexual side effects, others may find their sexual desire and function significantly impacted by the pharmacological reduction of this potent androgen.