not 100% on a subject, I use recreationally Viagra, Cialis, and amazon or eBay based adam secret 1500 and Viagra gives me most of the headache. Your primary care physician can prescribe you 1st two (generic version and online pharmacy will send it to your home). I like 3rd one mostly because of working time - about 48 hours after 2-3 hours after you take it so no need to plan ahead precisely. I do not see any issue (for me at least and one of my friends) to mix Adam Secret with some alcohol when 1st two are not recommended and I did not try. I know one guy who uses Viagra AND Cialis together but it causes him a very strong headache. For me 1st few times of using Adam, I had a heart palpitation but now it only gives me some light flashes and sweating after approximately 2 hours, and that how I know it started to work. So far no health issues after 2 years. I tried Adam Secret with Viagra or Cialis (but not both) - did not feel much of the difference but lost sensitivity, i.e. it took me almost an hour to finish and sometimes longer and I am talking with someone less than half of my age and very energetic and attractive. If anyone can provide some feedback (mostly on sensitivity for me) that would be appreciated. There are some new (higher potency) Adam like 2000 and 3000 (or platinum in the new package) that I did not try yet.