I have 20 gel caps of robotussen and was wondering, if i took them all, how long would the trip last and how intense would it be?
effects would take about 1 hour to peak. You would be peaking or near peaking for 4-6 hours, then would spend another 2-4 coming down.
it depends on how much you weigh. although, in general, 300mg will put you at a second plateau- expect a lot of sensory flanging, hopefully euphoria, confusion, a LOT of motor disruption, etc. i don't have any experience with gelcaps, i just drink DXM only syrups. i do this because i like to sip it slowly; i've found that taking it all at once causes the come up to be sort of harsh and a little too jarring. but with syrup, it always takes at least an hour to come up, i peak for maybe 3 hours, and come down for about 2-3. say you swallowed them all right now (11:18 PM where i live), you'd probably be tripping reasonably by 1 AM and by maybe 7 AM you'd be fine.