There's a myth out there that finasteride (an ingredient in Locklab) lowers testosterone. The truth is surprising because it's the exact opposite of the myth: when you take finasteride, your testosterone levels usually see a slight increase.
Research shows that a 5mg daily dose of finasteride for BPH can increase testosterone by 15 - 25%. But not everyone experiences this change. In a 2019 meta-analysis covering almost 1,800 participants, average testosterone levels rose about 27 percent across all studies, but results varied. Essentially, men with lower starting testosterone levels saw a boost, while those with already high levels didn’t. The jury is out on whether this spike in testosterone is meaningful or short-lived, and since Locklab contains 1.1mg of finasteride, the change would be lesser.
Testosterone is universally understood to improve sex drive and mood (Source). So, when Locklab patients report greater sexual well-being while treating hair loss, could it be from testosterone increasing? While it's possible this could contribute, it's more likely the 5mg of minoxidil (a vasodialator) is increasing blood flow to the penis—potentially enhancing erections. Furthermore, since sexual well-being is largely mental, feeling confident about your hair can be an automatic upgrade to your sex life.
Finasteride works by blocking 5-alpha-reductase, the enzyme that turns testosterone into dihydrotestosterone (DHT)—the main culprit behind male pattern hair loss. DHT attaches to androgen receptors in your hair follicles, gradually shrinking them and causing hair loss. Locklab blocks ~65% of the conversion of testosterone to DHT. Meaning, you stop losing your testosterone to DHT and therefore keep more of it.
Whenever you increase your testosterone, whether from taking finasteride, using testosterone replacement therapy (TRT), or by any other means, you always increase your estrogen slightly. That's just how the body works - because some testosterone is always aromatizing into estrogen, so more testosterone always means more estrogen. In extremely rare cases, that increase in testosterone also tips the scales to estrogen excess, which may have negative effects.
It’s best to consult a healthcare provider about testosterone levels, side effects, or treatment changes. Or, if you're taking Locklab, you can message your provider directly inside the Locklab Portal.
