It definitely works and I would say perfectly! Before I even completed a week, I saw spectacular results in muscle recovery. Combined with 5mg Optimum Nutrition Micronised Creatine and Dymatize Iso 100 protein, I achieved full recovery from the first 24 hours, while without these, it took me 2 to 3 days for my muscles to recover after training. I did tests (one week without and one week with HMB) and saw a difference I didn't expect. The immediate difference was in recovery and endurance (I was panting less). It also helps quite a bit with hypertrophy, but that starts to show more gradually. The capsules, although large, go down easily. Strangely, I don't feel them at all in my stomach, nor did I see the slightest side effect, so from a quality and performance standpoint, I have only positive things to say about this product. If I were to find something negative, it's that you have to take 5 capsules (3 an hour before training and 2 after) plus you do it a little differently on days you don't train (it has instructions on the back, they are easy, just a few days and I got used to it). Don't forget that healthy eating and proper sleep are everything if you are exercising (or doing heavy work). Supplements just help a click more. Everything needs to be on the right schedule to see results. This specific HMB is the most quality supplement I have taken in capsule form.