I take my prescription of Tianeptine medicinally (3x12.5 mg/day), and occasionally semi-recreationally (2-3 daily doses of 37.5 mg each in one evening against social anxiety), and it works well for both.
If you keep exceeding the 37.5 mg per day regularly though, tolerance builds fairly quickly. It is a µ-opioid agonist after all, so you might not want to buy several grams of tianeptine powder if you've had addiction issues with opioids.
Also, some people I've talked to find the drug a bit too stimulating, to the point where it actually increases their anxiety.