Best alternatives with lowest risk of negative sides, then?
Virtually every supplement has some sort of side effect e.g. A.I.'s tend to flare up joint pain as they dry you out while increasing testosterone.
Even something as beneficial for overall health like fish oil acts as a blood thinner,which can cause problems for some users.All choices that one makes when considering supplements have to be careful,it all comes down to looking over the risk/benefit factor.
That said,DAA is pretty safe at the dosage used in the well known study that showed more than a %50 increase in test in men.The caveat being that one should not use DAA for extended periods of time to minimize the risk of the side effect that you're concerned with.
Running DAA at 3 grams a day for 4-6 weeks is pretty damn safe,I'd say. The issue with NDMA receptors is merely one of over stimulation so if you don't use over the studied amount for months on end,no worries.
I haven't been around the boards much lately so I'm unaware of any other test booster with a better safety profile than DAA.Even so,I doubt such a product is available.
I will however add that I have been using Andro Factory's Focus for the past 3 weeks and change and I'm loving it.I'd say that any risk with a decline in cognitive processing via DAA would be negated by running Focus along with DAA.It'd make for a potent stack to increase testosterone and mental acuity without a need for post cycle therapy.