I was just discussing this with a friend the other night, and want to add my perspective...
I rolled for the first time in 2000. I was 19 at the time. I was into harm reduction and had a testing kit. I rolled once a month, not more. At that time, you either got "good" pills, or you got "bunk" pills. The good pills were mind blowing, loved up, energetic, and world changing. As was stated earlier, even the air touching you felt different and amazing. Shortly after I started rolling, I found one supplier who had very reliable pills. They always tested black with the testing kit, and I sent some of them to the Dancesafe lab and they were tested as being MDMA. A few presses that I had were yellow alligators, pink stunners, and red mickey mouses.
From 2000-2005 I always got my pills from the same person, and I always had the same experience. Worst case scenario was that you needed to take two pills instead of one in order to reach the desired effect.
In 2005, my reliable supplier quit and went on to live a normal family life. At about that same time, there was a major bust in the area and a smuggling ring was shut down. I had never really been part of a "scene" and I did not know where or how to find anything. Eventually, I found somewhere to obtain MDMA powder in capsules. Yes, it was tested at a lab. It was found to be MDMA as well, but there was a byproduct from the manufacturing process.
The experience from the capsules is 100% different than the experience from the pills I used to get. The old pills used to hit like a ton of bricks in about 20 minutes, with eye jitters, jaw clenching, high energy, and total euphoria. The capsules take about 45 minutes to hit, and are sleepy, relaxed and low energy. I could take 3 capsules and still never get the same feeling as the pills. I have tried molly from a few other places with the same results, I have tried different doses and had the same results. Other people agree with me. Also, sometimes the capsules make me physically sick days after I roll. I never had that with the pills, and there were times I took way more than I should have.
I would be inclined to think it was a personal tolerance issue if it was not for the reviews of other people I know. Also, I find it highly unlikely that my tolerance would have magically developed at the exact same moment I changed suppliers. Why would my ability to roll be intact one month but gone the next month?
I have to agree with the people in this thread who state that something is different. I do not pretend to know what it is, but I know that this feels like a completely different drug even though the same lab identified MDMA in both the pills AND the capsules.
I was wondering if it could have something to do with where the pill/capsule breaks down within the digestive system. A change in where it breaks down could impact how it is absorbed. It also seems possible that a manufacturing byproduct is somehow inhibiting the MDMA absorption/effectiveness.