This mirrors my experience exactly; always purchased from a couple different reputable peptide sites. How long it lasts and how soon it kicks in seems to differ by whether I inject SubQ vs IM. IM kicks in sooner, but doesn't last as long but it's not a dramatic difference either way.
I'd love to get my wife to try it, but with the nausea I experience I won't even broach the topic. See for me, it's worth the (passing) nausea for the end result - for her it would kill the whole weekend and would sour her on the idea of a repeated trial at a different dosage.
At least she's on TestCyp but she's cut her dosage enough that the effect has diminished the point of being measurable but not noticeable.