People have been sending me tianeptine sources for anyone that asks, so here's a quick compilation of them. Tianeptine is only meant for research purposes in the US, so these shouldn't be taken as a supplement without a doctor's supervision:
Tianeptine sodium salt.
COA may be available on request.
Special-purpose option: tianeptine sulfate
This form is more expensive, but can have benefits in some situations over regular tianeptine sodium salt. See Ceretropic's description for details.