How much tianeptine have you been using?
In any case, there is no over the counter opioid that is remotely similar to tianeptine. I mean, pod tea can certainly be just as strong in terms of absolute strength, and of course, is actual stronger in the sense, that one can overdose on pod, far easier.
But the unique, fast-acting feel of it isn't replaceable, by any over the counter substance. It is unusual substance, as despite its strength. it's quite hard to overdose on it, despite it simultaneously being a strong opioid due to too it's comparatively minor respiratory depression. It is like oxycodone-light, or diet-oxycodone. I suppose the closest thing would be some strong kratom extracts. But even then, it's not very similar. It is interesting because tianeptine is a strong opioid that is incredibly addictive, yet is still legal in most states and readily available. There is really only one reason for this, it doesn't cause alot of overdose deaths (particularly, tianeptine alone). If it didn't have that quirky comparative lack of respiratory (relative to its strength), it would have been federally classified as schedule I controlled substance by now.
Long story short, tianeptine is an odd ball drug, and there is no over the counter substance that is comparable. Kratom extracts are the closest in theory, but practice, kratom extracts feel very different than tianeptine.
I've had a few run ins with tianeptine, once was fairly serious, getting hooked on a few grams a day. I'm thanking that I live in an area where those gas station versions are available (like "tianna" or "zaza"), because despite them being way overpriced for the amount of tianeptine they contain in a bottle of capsules (I've always bought my tianeptine as bulk pure powder), I can easily see myself buying the bottled version at a gas station if I were say, on the way to Thanksgiving dinner at my girlfriends house, or somewhere else I don't want to be, and would quick to cough up the cash so I could go there feeling toasty and comfortable.