It was probably something that combined Kava Kava, Kratom, Valerian, Poppy, and maybe GABA/5-HTP. There are lots of these brews sold from various headshops, health-food stores, and vitamin shops. Some come from fairly unethical vendors from countries like China and India and may contain potentially dangerous things like DXM, BZP, methylone, and hell knows what other research chemicals besides. I'm not going to link anything for obvious reasons.
The best way to deal with stress is to confront whatever is causing stress in the first place. Don't look for chemicals to make you hide from your problems. That's fine and dandy if all you want is an evening of peace, but it is very easy to transition from taking an occasional break from stress to simply spending every evening on the same drug being peacefully oblivious while your life continues to slide further and further down whatever road that made you stressed out in the first place. And before you know it, you've picked up a drug habit, legal or not.
Still, if you're looking for herbal stress relief, try Kratom, but don't overdo it! The active ingredient in Kratom, mitragynine, is somewhat similar to tryptamines structurally but acts on the mu- and delta-opioid receptors and is basically an opiate pharmacologically. So, it's bound to be physically addictive in the long term! In the short term, it can provide wonderful stress relief and pain relief. It's energizing in the lower doses and sedating in the higher doses, and while it physically impairs you somewhat (don't drive!) it leaves you mentally clear.
Kava Kava works too, and is definitely not addictive in any way. In lower doses is it relaxing, calming, and takes away social anxiety. In higher doses it will put you into a very interesting, mentally unclouded but emotionally open and receptive (and vulnerable) state. I would stick to lower doses for stress relief purposes, since higher dosages have a tendency to pick up whatever emotions you're feeling and amplify them, so that if you're down and stressed out, you can get even more down and stressed out. At higher dosages it's more of an intoxicant, but a good one.
There was a study that claimed that Kava Kava causes liver damage, but that study was deeply flawed and was refuted. Still, it's something to read up on. Make sure that you use either only ground root, or use a product/extract that was only made from the root. The rest of the plant contains toxins, but the root is very safe.
A weak MAOI like Passionflower could work as well, but when you're messing around with MAOIs you absolutely must follow certain dietary and drug interaction precautions. The penalty is pushing up the daisies. Read up on this if you intend to go this route. If correctly used MAOIs are very safe, not addictive, and Passionflower is a very weak MAOI to begin with.
St. John's Wort is believed to be an SSRI, and I wouldn't touch SSRIs with a 10 foot pole, much less by brain. Still, it's widely used for minor depression and anxiety treatment.
5-HTP never did anything for me past some stomach discomfort and a more vivid visual quality to my dreams - as if I needed any more of that already. Still, it's safe enough to try as long as you're not using MAOIs or SSRIs of any sort.
None of this stuff is illegal in the US, though Kratom may be heading that way pretty soon.
Don't medicate your problems. Work them out.
