I have not. But it would be curious to try.
I am not sure it actually works exclusively by elevating GABA directly. Why?
1. Ordinarily every drug that stimulates GABA-A or GABA-B produces dose-dependent sedation. Picamilon is apparently sedating at low doses and stimulating at higher doses.
2. Given that stimulating GABA-A or GABA-B (A especially) will produce respiratory depression in excess, a drug that drastically elevates GABA should in theory pose a risk of respiratory depression and death. Picamilon seems to neither produce respiratory depression at any dose, and is not toxic at all -
this reference claims it takes more than 10g/kg orally and 6-10g/kg injected in mice to kill 50%. For comparison table salt's LD
50 is around 3g/kg orally, and even sugar is 30g/kg orally.
3. GABA-A and GABA-B agonists produce typical dependence and withdrawal symptoms. Picamilon seems to produce neither dependence nor withdrawal.
That said there are studies showing it does works as an anxiolytic... somehow. But it doesn't seem like typical GABAergic effects.
Another one to look into is Selank. I once tried some as a nasal spray, and though I am usually not troubled by anxiety, it did take the edge off some unnerving situations. (I wanted my often-anxious friend to try some but he never got the chance...)
In the total opposite of what you asked for, there is a 4-amino-acid protien called CCK-4 (derived from a gastric hormone called cholecystokinin or CCK through chemical synthesis, and not present naturally) whose effect when injected even in tiny doses (50 ug) causes massive panic attacks (without any other actual direct physical effects). It's sometimes used (with consent of course!) to cause anxiety in a fairly safe, consistent, reliable, on-demand fashion in studies testing new anxiolytic drugs, because making people have a panic attack usually takes some work, could be of differing intensity, and is specific to every individual. And thankfully it has a half life of 13 minutes, so in the worst case it will take 90 minutes to be eliminated, but thankfully the worst would be over in 15 minutes (which admittedly would feel like forever, but imagine if it was a half life of 13 hours... it would be a war crime to dose it.)
Somewhat jokingly, I say it should be added to the local "down" supply, as an aversive agent to make people innately dislike the sad, toxic, mislabeled excuse of mixed sedatives that are sold as "heroin" here. (often mixes of fentanyl, carfentanil, superpotent benzos, and even xylazine, and rarely if ever any actual poppy-derived heroin). It's to the point doctors will literally prescribe dozens of injectable 8mg Dilaudids delivered daily for free, in addition to methadone, just to get addicts to stop ODing and ending up with dual opioid/benzo withdrawals.
By all rights you
should be panicking if you use the filth sold today. Superpowerful opioids and superpowerful benzos and even toxic cuts... what are you even thinking? There's no way to use it safely, and no easy way to know how much of each drug is in the mixture (and also no way to easily ID the benzo). Want heroin? Get in line for the time machine to 1975.