Hydrocodone's peak plasma concentration levels occur approximately 1.5-2 hours after ingestion. Plasma half-life is about 4.5 hours.

This does not change with tolerance to the medication. The euphoric and analgesic effects ARE affected by tolerance.

Hydro works for me (keeping in mind that I use methadone and oxycodone on a daily basis, but I do occasionally get scripts for hydro) approximately 45 minutes after I take it and the noticable effects last for approximately 3 hours. If I take it for more than a few days the medication becomes nearly useless (probably due to cross-tolerance and the much stronger and larger doses of my other pain meds.)