I think plain DAA is very hit and miss for most people. When it comes with Sarcosine results seem better.
according to who and based on what pred?
Most of the feedback on DAA seems to be positive. The feedback on our DAA calcium chelate and sarcosine product has been great. I've posted some
feedback on our product at your request before (including from one UK user). In addition, here's a couple of guys saying they didn't like plain DAA but enjoyed our product:
"i took bulk DAA for 6 weeks at 5 grams and felt nothing. i switched to [brand removed] and within 3 days my libido increased. a couple weeks later i felt like i was 16 and horny."
"To me there are a couple obvious differences between bulk DAA and [brand removed] just from how I feel after taking it. For example, bulk DAA gives me wicked anxiety while [brand removed] doesn't."
Anecdotally, it seems that there may be more reports of digestive discomfort with bulk DAA than with our chelated DAA as well, though I have nothing to substantiate that.
If you'd like to understand the reasoning behind the addition of sarcosine to potentiate the effects, you can check out this writeup
[Warning: science] The cliffs are that the NMDA receptors that DAA binds to have two binding sites, and both must be activated by different compounds before the receptor is activated (and the benefits of DAA are seen). DAA attaches to the Glutamate binding site and Sarcosine attaches to the Glycine site, ensuring that the maximal effects will be seen from a given DAA dosage. [see wikipedia
for more on NMDA receptors]