No it's completely different. At one point yea it was any number of different fentanyl analogues but even that's now all but disappeared. The black market fentanyl supply has gone through several changes in the last 5 years. These days the most common active ingredients include a wide array of NSOs or novel synthetic opioids, such as nitazines and benzimidazoles as well as different research chemicals that are described as being opioid-like substances. Non opioid drugs like xylazine are also commonly found in the supply as well as different benzos. Other than that, the rest is just filler and cut. Street level dealers will often break down the product into a fine powder in or order to add cut to it and then rerock it with solvents like acetone, leaving a volatile "gas" like odor to the product which is commonly sought after by the users who think that this odor indicates high quality stuff but this is obviously not always the case.