Actually most hormones are proteins (insulin etc). Test is a lipid hormone
yes.
as i said, testosterone is derived from cholesterol, which is a lipid
GH, peptides, insulin etc all consist of a certain amino acid sequence = protein structure
except for GH most of them are pretty stable though. i dont know about heating but insulin never really goes bad, you can toss it around, throw it against the wall and theres pretty much no degradation over time whatsoever.
steroid hormones dont have a protein structure. they are VERY stable.
as primemuscle said the only issue is if your gear gets too cold, however that doesnt destroy the hormone either. it just makes it come out of solution with the oil.