I recently have been using a few products containing S7 and have noticed better pumps/endruance during my training. I also used Gains Candy from Alpha Lion, which is S7 as a stand-alone ingredient with Astragin to help with absorption. Here is a little background information on S7 and its potential as a potent Nitric Oxide booster.
Unlike other nitric oxide (NO) boosters, which provide an external source of nitrates, FutureCeuticals’ new S7 (SPECTRA7) - reportedly helps the human body produce its own NO to increase levels. S7 is a blend of 7 different botanicals consisting of green coffee bean extract, green tea extract, turmeric extract, tart cherry, blueberry, broccoli and kale.
This clinically-researched blend of seven plant-based ingredients has been clinically shown to boost nitric oxide (NO) levels in humans by an impressive 230% over baseline.
Data published Here showed that the small pilot study
Personally, I have loved using Gains Candy as and addition to my pre-workout. It's also popping up in more pre-workouts across the industry. Being relatively cheap in price, I think it's well worth the investment.