For Sendure, just mix it yourself for a fraction of the price. Bulk Supplements on Amazon sells Beet Root extract and Citrulline-L Malate cheap which, IIRC, are the main ingredients you're looking for the nitric oxide supplementation. The photos at that link have the portions you want for one serving. I did this previously for a couple months and, anecdotally, as a beginner-ish (2~3 years) climber at the time it made a huge difference in helping me climb without getting pumped. I absolutely recommend trying it if you're getting pumped a lot during your sessions.