I remember I ordered some tianeptine sodium like a year after I quit opiates. I had no idea it was a mu opiate receptor agonist, I was just reading reports of people getting great euphoria at high doses. I took 60mg, and I was like, whoa, this feels almost like an opiate! I took it in various doses for 3 days, up to 120mg I think. I got fairly noddy at higher dosages, it was really very euphoric, it felt like a full-on opiate to me. On the third day I was reading about it more and saw that it is a mu opiate agonist, especially at higher dosages. I was like, fuck, I just took this 3 days in a row, and I wanted to never take an opiate again. I gave it to my friend who ended up abusing the living shit out of it and having a month of withdrawals she said felt like a cross between strong opiate and SSRI withdrawals.