What did the TRAVERSE sexual function study find?
It is the largest placebo-controlled look at this exact question. Within the TRAVERSE trial, 1,161 men with low libido were enrolled in a nested sexual function study. All were aged 45 to 80, had two testosterone levels below 300 ng/dL, had symptoms of low testosterone, and had heart disease or high heart risk. They used testosterone gel or a placebo gel.
The results split cleanly:
| Outcome | Testosterone versus placebo |
|---|---|
| Sexual activity | Higher activity scores at 6 and 12 months, maintained at 24 months |
| Sexual desire | Improved |
| Hypogonadal symptoms | Improved |
| Erectile function | No improvement |
So TRT raised desire and how often men were sexually active, and kept doing so for two years, but it did not make erections better on average.
How does that compare with earlier trials?
Earlier results point the same way on desire, with a smaller and less consistent effect on erections. In the Testosterone Trials, men 65 or older with testosterone under 275 ng/dL had significantly more sexual activity, desire and erectile function on testosterone gel for a year, which the authors summed up as a moderate benefit for sexual function.
The AUA guideline reflects both findings, telling patients that testosterone therapy may improve low sex drive and erectile function. The fair reading is that libido is the more dependable gain, and erections may or may not follow.
What if your testosterone is normal?
Then TRT is unlikely to be the answer. Every trial above enrolled men with confirmed low levels, and the Endocrine Society’s 2026 statement stresses that symptoms alone are not diagnostic. Our answer on TRT with normal testosterone covers the narrow exceptions.
Low libido has many other drivers: depression, stress, poor sleep, relationship strain, alcohol and medicines such as some antidepressants. A high prolactin level can also lower desire, as MedlinePlus notes, and the AUA recommends measuring prolactin in men with low testosterone and a low or low-normal LH. Our pages on low libido in men and blood tests for low libido cover the workup.
When does erectile dysfunction need its own treatment?
When erections, rather than desire, are the main problem, or when desire returns on TRT but erections do not. That pattern fits the TRAVERSE result, and it suggests something besides testosterone, such as blood flow, nerves or medicines, is involved.
ED treatment can run alongside TRT. Options include oral and topical medicines, compounded Trimix and Quadmix injections, and other approaches your provider can explain. Our answer on whether the problem is low libido or ED helps you tell them apart, and our page on taking Cialis and testosterone together covers the combination. See also our overview of erectile dysfunction treatment.
Separate from any booking: an erection that lasts more than 4 hours is an emergency, so call 911 or get to an emergency room right away.
Related question: how soon would libido change?
The TRAVERSE study reported the difference at 6 and 12 months and found it still present at 24 months; the Testosterone Trials measured over one year. Individual timing varies, so judge progress over months rather than weeks. Our article on how long TRT takes to work sets out a realistic timeline.
Getting low libido evaluated at Ultimate Male
At San Gabriel or Downey, a low-libido workup starts with on-site labs, including the TRT pre-screening panel, and a one-on-one consultation with a PA-C or MD who asks about desire and erections separately. That distinction shapes the plan.
If low testosterone is confirmed, testosterone therapy may be part of it, with ED treatment added if erections need it. If testosterone is normal, you get a clear look at the other causes. Start with the free 10-minute call, then book your evaluation.
