Not sure where to post this but I figured here might be worth a try.

Was recently told my gf of 10 years has been unfaithful on a few occasions by a friend of mine. I confronted her (stupidly) and she flat out denied it all adamantly. She insists that she's fiercely loyal and has agreed to do a lie detector or take a truth serum to prove it to me. (Obviously there is a lot more detail involved as to how we got here)

My question is, is there an actual truth serum available that I could ask her to take? I know it all sounds a bit extreme but I've been following this sub for a while and honestly I'm having serious trouble taking her at her word.