Erection problems and low testosterone are often mentioned in the same breath, and they can overlap. But they are different problems with different treatments. ED tablets help blood flow when you are aroused; testosterone treatment replaces a hormone your body is not making enough of. Here is how to tell them apart.
Does Cialis or Viagra increase testosterone?
No. In studies of men taking tadalafil (Cialis) 10 mg or 20 mg daily for six to nine months, there was no effect on testosterone or the hormones that control it1. Sildenafil (Viagra) and the other ED tablets work on blood vessels, not on hormone production2. So an ED tablet can help with erections, but it will not fix low testosterone or the symptoms it causes.
How ED and low testosterone differ
| Erectile dysfunction | Low testosterone (hypogonadism) | |
|---|---|---|
| Main problem | Difficulty getting or keeping an erection | The body does not make enough testosterone |
| Typical sexual symptoms | Erection problems; desire may be normal | Lower sex drive, fewer morning erections, and erection problems3 |
| Other symptoms | Usually none from the ED itself | Low mood, low motivation, tiredness, less physical strength3 |
| Usual first treatment | ED tablets (PDE5 inhibitors)4 | Testosterone treatment, if low levels are confirmed3 |
The two can happen together. Low testosterone is one of the hormone causes of ED, and men with ED are often checked for it45. A clue is low desire: if you have lost interest in sex as well as having erection problems, it is worth asking about a testosterone test.
How low testosterone is diagnosed
Symptoms alone are not enough, because tiredness, low mood and low desire have many causes3. European guidelines recommend3:
- a blood test for total testosterone taken in the morning (between 7 and 10 am) before eating
- repeating the test on at least two separate occasions if the level is low, before starting treatment
- checking other hormones to find the cause, and checking for illnesses or medicines that can lower testosterone
When testosterone treatment helps
- Only when testosterone is genuinely low. Guidelines say testosterone treatment should not be used in men whose testosterone is normal3.
- Mild ED with low testosterone: testosterone treatment can be the first treatment3.
- More severe ED with low testosterone: testosterone and an ED tablet can be used together3. In men with low testosterone who do not respond to ED tablets, adding testosterone may improve the response4.
- Men with diabetes often see only modest sexual improvements from testosterone alone and may need an ED tablet as well3. See our guide to diabetes and erectile dysfunction.
An important warning: fertility
Testosterone treatment switches off the body’s own signals for making sperm. European guidelines say it should not be used to treat male infertility, or in men who want to father children3. If you are trying for a baby, tell your doctor before starting any testosterone.
Can I take Cialis with testosterone treatment?
Yes, guidelines describe using the two together in men with low testosterone and more severe ED3. The usual cautions for ED tablets still apply, including never combining them with nitrates1. Testosterone treatment is prescribed and monitored by a doctor.
We do not supply testosterone. For ED treatments, see our ED medicines page and our guide to daily vs on-demand tadalafil. If tablets are not working, see Viagra not working?
ED tablets we supply include Cialis 5 mg for daily use, Cialis 20 mg and Viagra 100 mg. All need a prescription.
Frequently asked questions
Does Cialis increase testosterone?
No. Studies of tadalafil taken daily for up to nine months found no effect on testosterone levels.
Does Viagra increase testosterone?
No. Viagra works by improving blood flow to the penis when you are aroused. It does not act on hormone production.
Can low testosterone cause ED?
Yes, it is one of the hormone causes of erection problems, usually alongside lower sex drive and fewer morning erections. A morning blood test can check your level.
Should I take testosterone for ED?
Only if blood tests confirm your testosterone is low. In men with normal testosterone, it is not recommended. ED tablets are the usual first treatment for ED.
Does testosterone affect fertility?
Yes. Testosterone treatment reduces sperm production, so it is not used in men who are trying to father a child.
Sources & references
- US National Library of Medicine, DailyMed. Cialis (tadalafil) prescribing information.
- US National Library of Medicine, DailyMed. Viagra (sildenafil) prescribing information.
- European Association of Urology. EAU Guidelines on Sexual and Reproductive Health: Male hypogonadism.
- European Association of Urology. EAU Guidelines on Sexual and Reproductive Health: Management of erectile dysfunction.
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms and Causes of Erectile Dysfunction. Last reviewed October 2024.
Related reading
This content is for informational purposes only and is not medical advice. Testosterone treatment should only be started after blood tests and under a doctor’s care. Used as prescribed by a licensed medical professional.
Chitra Shetty is a licensed clinical pharmacist with 14 years of experience. She holds a B.Pharm and M.Pharm from Sambalpur University. At OnlineMeds, she reviews medicine and health content to help ensure it is accurate, evidence-based, and easy to understand.