Why TRT Does Not Always Fix Erectile Dysfunction
Men start testosterone replacement therapy expecting the whole package: energy, muscle, libido and erections. The trial evidence says the last one does not reliably follow. If your testosterone numbers have climbed and erectile function has not, that gap is documented, and this page sets out what the research shows and what to ask your prescriber.
Does TRT improve erectile function
Not reliably, on the largest trial evidence available. The TRAVERSE Sexual Function Study randomised 1,161 hypogonadal men with low libido, 587 to testosterone gel and 574 to placebo, and followed them for two years.
Testosterone improved sexual activity, hypogonadal symptoms and sexual desire. It did not improve erectile function. Those men were aged 45 to 80 with testosterone below 300 ng/dL and either cardiovascular disease or raised cardiovascular risk.
A 2024 Cochrane review of testosterone in men with sexual dysfunction pooled nine placebo-controlled trials covering 2,808 patients and found a statistically significant but not clinically relevant improvement in erectile function.
Earlier meta-analyses were more positive, particularly in men with more severe testosterone deficiency, so this is a field where the answer depends on who was studied. The consistent thread is that desire responds more readily than erections do.
Why testosterone and erections come apart
They run on different systems. Desire is largely hormonal. An erection is a vascular and neurological event that depends on nitric oxide, healthy arteries and intact nerve signalling, and testosterone is only one input to it.
That has a blunt implication. If erections do not improve once testosterone is corrected, low testosterone may have been a marker rather than the cause, and the real problem may be arterial.
Erectile difficulty is frequently the first visible sign of cardiovascular disease, which makes a non-response on TRT a reason for a vascular workup rather than a dose increase.
What else can work against you on TRT
Two things are worth raising with your prescriber, and neither is a reason to self-adjust anything.
Exogenous testosterone suppresses the pituitary output of LH and FSH. That is established endocrinology and it is why testicular function falls on TRT even when blood testosterone reads high.
Erythrocytosis, a rise in red blood cell count, is a labelled adverse effect of testosterone and is more common with injectable formulations. Whether thicker blood measurably affects erectile function has not been established, but hematocrit is monitored on TRT for its own reasons and is worth asking about.
Testosterone also converts to estradiol through aromatase, and estradiol has its own role in male sexual function. What the optimal ratio is, and whether adjusting it improves erections, is not settled, so treat anyone offering you a target number with caution.
What to ask your prescriber
These are questions, not adjustments. Dosing and monitoring on TRT belong to the clinician who prescribed it.
- Ask what your hematocrit is doing, not just your total testosterone.
- Ask whether estradiol has been measured and how.
- Ask whether a vascular assessment is warranted, given that erectile difficulty can be an early cardiovascular sign.
- Ask whether a PDE5 inhibitor alongside TRT is appropriate, since that combination has trial evidence behind it where testosterone alone does not.
- Ask about dosing schedule rather than changing it yourself.
What actually has evidence behind it
Prescription PDE5 inhibitors, and the cardiovascular basics. Those are the two things with a substantial trial base for erectile function specifically, and both belong in the conversation before anything else.
Weight, exercise and smoking status act directly on the arteries an erection depends on, and the research behind each is in the lifestyle habits guide. In one randomised trial, about a third of obese men with erectile dysfunction regained normal function through diet and exercise alone.
Where Herbal Mojo fits
Herbal Mojo is a seven ingredient supplement taken when needed. It is not a hormone therapy, and it has not been studied in men on TRT.
One ingredient matters on this page specifically. Eurycoma Longifolia, the largest ingredient at 154 mg, has been studied for its effect on testosterone, and a 2022 systematic review and meta-analysis of randomised trials reported a significant rise in total testosterone with supplementation, including in hypogonadal men.
Those trials gave the extract daily over a period of weeks, not as a single capsule taken when needed, and no study has measured testosterone after taking the finished formula. It is still a reason to tell your prescriber before combining Herbal Mojo with TRT, because anything with a reported effect on testosterone belongs in the conversation about your bloodwork.
What the evidence behind each of the seven ingredients actually measured, including where it is laboratory work rather than trials in men, is set out on the ingredients page. If you take anything for your heart, read the nitrate and blood pressure medication article first.
Common questions
Can TRT make erectile dysfunction worse? Some men report that. What the trial evidence establishes is that TRT does not reliably improve erectile function, not that it commonly worsens it. Raise any deterioration with your prescriber.
Does more testosterone mean better erections? No. TRAVERSE improved desire and sexual activity over two years without improving erectile function, because erections depend on vascular and nerve health as much as on hormone levels.
Should I change my injection schedule? Not on your own. Ask the clinician who prescribed it. Protocol advice from supplement sites is not a substitute for the person managing your bloodwork.
Can Herbal Mojo fix this? No. It is not a hormone therapy, no study has measured its effect on testosterone, and it has not been studied in men on TRT. If erections have not improved on TRT, the useful next step is a medical assessment.