Is ED a side effect of rogaine?

To the best of my knowledge, Rogaine (i.e. Minoxidil) has no impact on potency.  However, if you are experiencing the problem, I suggest stopping.

Minoxidil has not been known to cause erectile dysfunction. In fact, topical Minoxidil has been used to treat ED, though not with great success.

Erection Dysfunction (ED) is not one of the reported side effects of minoxidil.  However, It has been reported with the other hair loss medication (finasteride). 

At present there are no scientific studies that support any link between use of minoxidil and sexual dysfunction in men or women.  The Rogaine drug monograph and earlier clinical studies dating back to the late 1980s did not list sexual dysfunction as a side effect. In general, anyone concerned about a potential contribution should stop and speak with their primary care physician. It is important to be aware of how difficult it is to prove an association and why good studies absolutely need to be done before implicating such medications. How common is sexual dysfunction in the population ?10% or more of men in their 20s, 30% of men in their 30s and 50% of men 40-70 and 70 % of men over 70 will have some degree of sexual dysfunction. Alot of men also use Rogaine. Sorting out cause and effect is challenging and requires meticulous design and interpretation of the studies.

There are no reports of an association between Rogaine and Erectile Dysfunction. I would consult with your primary care doctor for this concern. 

Erectile Dysfunction is not a known side effect of the drug minoxidil. This drug is generally safe to use