I never made it to the 4 week mark, but that was because of me, not the product.
The package says it's good for one use, but I've used it twice and still have left over product. I have natural, dry, coarse, high porosity hair that ranges in length with the longest being BSL. My hair is in the type 4 family with a bit of 3c in the nape.
The product is simple to use and comes with a set of easy to follow instructions on and inside the box. The shampoo says it's "moisturizing," but it's not. It acts like a clarifying shampoo leaving your hair squeaky clean. The consistency is light and is somewhere between water and a serum, but leaning more towards water. My curls were popping after I used it! I liked the shampoo so much that I would buy it separately if they offered it.
The next step is the "inter-active" leave-in. The consistency is similar to the shampoo, but a bit thicker - still lighter than a serum though. After applying, you wait 20 minutes, then proceed to the next step of blow-drying. I felt a coating on my hair after applying the leave-in, but the instructions said that could happen and it would disappear after flat ironing, and it did.
Once I finished blow drying my hair, I immediately flat ironed using the comb chase method. The end result was soft, light, straight hair with lots of swang! I didn't have the silky "relaxer look" I go for when straightening my hair though, so the next morning, I parted my hair in 4 sections and applied a small amount of oil on each section before lightly flat ironing. THEN I got the silky, just got a relaxer look I was going for. When I did the system for a 2nd time a while later, I found that again, I had to use a bit of oil to give me my desired results.
My hair held up very well through sweat and humidity after my first use. My roots are usually quick to revert, but I didn't have that problem after the TMS. I sweated way more after my second use (it was my brother's graduation and not only was it hot, but we were packed like sausages trying to leave) and I found that my roots around the perimeter did become a bit wavy, but with the use of a soft brush and a scarf, it went ALMOST back to the way it was. I didn't have any type of edge control product, but I'm sure that would've done even better. Both times I made it around 2 weeks before washing, but only because I wanted my curls back.
My hair reverted back to normal after my first use, but it definitely loosened my curls after the second.