I am a skinny marathon runner, and I don't gain muscle mass easily. An injury curtailed my running, so I decided to rework my fitness regimen to focus on weightlifting. I bought CellTech at the recommendation of a friend and tried it for 8 weeks, following the directions exactly.
The first thing I noticed was the foul taste of the CellTech. I choked down the Grape flavor twice a day for 5 days (the "loading" phase), and then switched to a once-daily serving of the Fruit Punch flavor, which is more palatable. It still has a sickly sweet chemical flavor, a somewhat gritty texture, and a strong vile aftertaste. Twice I drank the CellTech too quickly and vomited it up.
I lifted three times a week, with an upper/lower body split. A typical workout was 5 exercises: 5 sets each of 2 compound exercises, and 3 sets each of 3 isolation exercises. The last set of each exercise was done to failure. I also consumed 30 grams of whey protein drink twice per day.
I am mostly pleased with the results. I noticed I was recovering faster between workouts than I expected. I had greater stamina, and my muscles felt "pumped up" during each workout. I increased my 10-rep bench press weight 40 pounds, and my 10-rep squat weight by 55 pounds. I gained about 10 pounds, and most of it appears to be muscle. My body looks more muscular, and others have commented on it. I also gained a small amount of body fat. I believe this is because CellTech contains as much pure sugar as 2 cans of Coke.
I experienced constipation and dehydration from this product, as well as occasional nausea, despite drinking a gallon of water per day.
It does have a measurable effect on bodybuilding performance. However, I think only dedicated bodybuilders and well-disciplined dabblers will be able to stick with the recommended 8-week usage pattern. You may be able to get a lot of the same benefits with a much less expensive and tasteless creatine powder.