Medications like Viagra are known as PDE5 inhibitors. They help improve blood flow to the penis by supporting the body’s natural nitric oxide system. But that system needs testosterone to work properly.

In men with low testosterone (under 10nmol/L or free T under 180pmol/L), PDE5 medications often don’t work well - because the nitric oxide pathway doesn’t fire as it should.

Recent studies found:

• Up to 90% of men who didn’t respond to Viagra improved when testosterone was added.
• Improvements included better erection quality, orgasm, and overall sexual satisfaction.
• The benefit was strongest in men with very low T levels.
• A short course of testosterone alone had limited results - but combining it with ED meds worked much better.

If you’ve tried Viagra or Cialis without success, your testosterone could be part of the problem. In men with proven low T, adding testosterone therapy may help these medications work the way they’re supposed to.

You can request lab testing to check your testosterone levels here.