This shirt from TERODACO provides extra sweat if you wear it during exercise.The shirt is made of polymer and spandex fabric. The inner thermogenic polymer fabric increases the core temperature to promote sweating, while the outer performance compression fabric instantly slims and shapes your figure. This shirt is also intended for increased sweating during exercise with the waist slimmer to have stimulation of the sweat in the right spot . Take note that you can wash this by hand or by using a washing machine.At first, I had the impression that this was just like a normal spandex T-shirt, but I was wrong. The material and quality of it is pretty decent, and upon wearing it, I feel that the inner thermal polymer fabric increases my core temperature, which is nice. It also feels like it is not breathable, which simply promotes the perspiration of my skin during heavy workouts. So far, it seems effective for perspiration during my exercise, but just to clarify that the effect will vary from person to person.All in all, I would say that it is quite effective. It is a durable and well-made product that can withstand even heavy usage. It's a bit pricey for a piece of shirt but it has a specific purpose, so I would recommend this one.My husband got this as he thought he needed it. Although I don't really see it myself, he wanted to give it a go so I went ahead and got it. At first appearance, it looks like a normal t-shirt, but on further inspection, the interior is shiny and has a smooth feel. The idea is it makes you sweat and therefore lose weight. Okay, this is where I lose faith....just because you lose sweat does NOT mean you are going to gain muscle as in the picture!!! Losing sweat means you lose fluids from the body and therefore lose a little water...not weight!Unless I am completely misunderstanding this, which isn't actually hard considering my brain these days, but I would say this is not a magical way of gaining muscle and losing weight. Sweating = losing water that is easily replaced.As I say, I am not an expert in this field but do know that losing fat and gaining muscle is all about eating correctly and exercising the muscles to gain definition. No t-shirt, or whatever they claim, is going to help that. Unfortunately, I could only bring myself to give this a humble 2/5. Good try and may be suitable for some, but just not us.After wearing this shirt a couple of times, I could definitely feel myself sweating more as it does a good job at increasing body heat.Compared to others, this feels pretty comfortable and not too tight - has a bit of stretchiness to it.I'm not expecting to see any massive changes that would be entirely attributable to solely this shirt, but wearing this and sticking to a good exercise plan and healthy diet should help lose the pounds a bit quicker hopefully.Not currently available for purchase, so unable to comment on whether this is good value or not.Overall, quite good and does a good job in keeping heat in and causing you to sweat more.Wow, if this garment is supposed to make you sweat then it sure does deliver! It does have a petrol/fishy kind of smell, due to the fabric used but it’s not overwhelming. The fit for my fat little body was perfect (snug in all the right places) and still gave me full freedom of movement. After 20 minutes of running it felt my body was wrapped in foil and in an oven but I could definitely feel it working. The shirt was soaking wet inside after using it and I had to turn it inside out and hang it out to dry as I can’t really be washing it after every use, but it seems fine and not smelly. Unfortunately I don’t quite look like the model used to advertise the product but can see how this kind of a product can help with my fitness routine.The appearance is like a normal T-shirt, because the inner thermal polymer fabric can increase the core temperature, but it is not breathable, which simply promotes the perspiration of the skin during exercise. However, the effect varies from person to person.If you sweat easily during exercise, it can increase your perspiration. If it's not easy to sweat, use it as a sports t-shirt to cool you down, you'll burn your fat during exercise, and when the heat builds up, your skin will start to sweat. It is very effective for perspiration during exercise, but the effect will vary from person to person.For size, if you want more flexible movement, go one size up. If you like tights, buy them in normal size.