I did 295 mg DXM last weekend (i also wanted to try it at least once
).
But it isn't interesting, you're just feeling really weird for quite a long time (6-8 hours) and the day after you're also not feeling really well. And it's not an Entheogen, it's absolutely not interesting (for Psychonauts).
But ok, try it and you will experience it.
The best thing that you could do is to buy "Daro Retard Capsules". If that's available in your country.
This is the cheapest and healthiest way to take DXM from cough medicines.
A package here has 10 capsules with 29,5 mg DXM each.
Note that 1 capsule has 40,2 dextromethorfanhydrobromide-monohydraat (don't know the English translation), but that's the same as 29,5 mg DXM. It isn't something to worry about, but i'm just telling you.
10 capsules with 29,5 mg DXM is in total 295 DXM, and that worked for me.
DXM oral dosages (source: Erowid):
Light 100 - 200 mg
Common 200 - 400 mg
Strong 300 - 600 mg
Heavy 600 - 1500 mg
Risk of Death 2,500 - 20,000 mg
After you buy it, open a capsule and empty it in a bowl and crush the tiny white balls in it.
It's easier to do this one by one, so you can be more sure that all the balls are crushed after you crushed the last capsule.
You need to crush the tiny white balls, because if you don't you don't get the DXM at once in your system.
The capsules are made to last for about 8 hours, so the tiny white balls in the capsule all have a different thickness, so that they don't open up at the same time.
The crushing can be done with a spoon or something.
After that put it in a glass and mix it with a liquid, and then you can drink it (not a nice taste).
You will need to fill up the glass for a several times, because the powder keeps sticking to the glass, but after that the onset will be in 30-60 minutes.