this is just my opinion/experieience but i woud say don't get on subs for pain. first of all, kratom is a much better painkiller than subs. subs suck for pain.
here is my experience with trying to use sub for pain. it works the first couple days, then your receptors fill up and it stops working. the only way it grants any pain relief (in my experience) is if you use small doses and wait 12 hrs between doses and even then it only gives you a little pain relief right after you dose and if you try to take more it means youll have to wait 18 hrs before you can get anything from your next dose. plus there is no muscle relaxation with sub so it doesnt help with muscle pain.
now imagine you find yourself in severe pain. you have to wait 12-18 hrs before you can take anything for it and even if you have other opioids on hand sub blocks them, so youre stuck using sub and only sub.
and it sucks being on sub. it blocks your emotions and makes life dull and doesnt have much recreational effect when used daily. kratom is far better. with kratom, if yoiure in severe pain you can take more kratom again in 3 or 4 hrs and it wil still work. also kratom doesnt block other substances so you can take kratom plus occasionally poppy seed tea or oxys or even sub meaning you save your sub for a really bad day but use kratom the rest of the time. the sub will work then cuz your tolerance will be low.
but yeah, sub for pain is stupid so many better options. there are also other herbs you can use along with kratom for pain like kava and akuamma seed. imo sub is useful for kicking dope or as a substitute for better opioids and thats about it.