Duration easily 6hrs . Made syrup at ratio of 56mg/oz. Mixed an oz into some drink. Drank about 2/3 (roughly 40mg worth) and let it kick in. Took a good 2 hours to peak although onset was maybe 30 minutes in. Stuff was stronger than hydrocodone for sure. Sedating, and lasts a very long time. Nausea made me puke like 5 hours or more later because I forgot to have lunch due to be tired and wanted to nap because of a poor quality sleep last night. Very nice sedation and relaxation, some itching but not too much, lasts a cool 6hrs . It was decently water soluble although didn't just absolutely disappear. It wasn't snow white. It was a bit off white. Presses together like corn starch. Tastes extremely bitter. It destroyed the flavor of sweetened seltzer. I had to add a lot of extra sweetener. I also added bubblegum flavor to the syrup.... Does this sound like odsmt or potentially something stronger and dangerous? I tested for fent multiple times and it's not fent. It supposed to be really pure odsmt, but I've never tried odsmt before, just hydrocodone, buprenorphine, codeine, and tramadol. It lasts well over 6hrs. I have tolerance for taking 50mg hydrocodone and over 400ng tramadol. This stuff is stronger with the dose that I took and lasts super long. Hands down stronger than hydrocodone, although hydrocodone is a pro drug, so it's possible that my body doesn't convert it to hydromorphone very well... Feeling way better now that I have eaten.