Is it safe to take arginine, or other supplements for sexual enhancement, while taking Viagra or Cialis?

Answer:

In general, it may be best to avoid taking sexual enhancement supplements if you are taking a prescription medication for erectile function, such as sildenafil (Viagra) or tadalafil (Cialis). There are concerns of potential interactions when taking these drugs with arginine, and certain other common ingredients in sexual enhancement supplements, such as horny goat weed.

In addition, many sexual enhancement supplements have been found to contain undeclared sildenafil and tadalafil, so that taking them along with the same prescribed medications for erectile dysfunction may result in too large a dose and an increase in side-effects associated with these drugs (see the list of Recalls and Warnings for supplements found to contain these drugs).

That being said, a particular form of carnitine, may increase the effectiveness of sildenafil in men with diabetes who had previously failed to respond to the drug, without serious adverse effects (mild gastric pain was reported).

Supplementing with vitamin D may also increase the effectiveness of ED drugs in men with low vitamin D levels.

Be aware that St. John's Wort and pomegranate juice may also interact with sildenafil and/or tadalafil. In addition, grapefruit juice and orange juice made from Seville oranges may interact with sildenafil, potentially increasing its effects (Jetter, Clin Pharmacol Ther 2002; Abdelkawy, Drugs R D 2016).