There is acute rebound & chronic rebound, maybe you are thinking of chronic in thinking it can't happen that fast?
As I understand it, acute is from a too-steep drop or too-low #, where their liver reacts. The drop or the low is followed by sudden highs, and then with that at times you can see a lower PS at the end of the cycle. That is one reason for doing full curves - if the #s drop mid-cycle, then go high more or less 3/4 of the way through the cycle, and then start dropping back down after that, that is the classic acute Somogyi rebound pattern. [ETA: I learned this stuff back on Vetsulin, and am not sure if there are different subtleties on PZI. Today's disclaimer.
]
Chronic rebound is high flat #s, and that kind takes some time to develop, from a dose that has been too high for a while (I don't know what the timeframe is).
So yes, by the highs at the end of the cycle it looks to me like it could be acute Somogyi rebound. I wouldn't overly panic though, and I'm not actually convinced that's what it is, because I am not seeing that steep a drop, or any #s that are too low. So to me that means there is no trigger that would lead to rebound.
I'm thinking it could be more in the liver training category. Not saying I'm 100% certain that is what is going on, just what looks probable to me. To me it looks like a nice breakthrough, followed by panicky liver. Heck, I'd panic if I were him & saw a 55, even if it is a perfect #! I saw some similar patterns with Bix - nice #s, and then all of a sudden a crazy 500-something at the end. Once he was in sustained good #s for a while, that kind of thing settled way down (and none of my trials of lowering the dose were ever productive).
If it is acute rebound, it should settle down hopefully in a cycle or two, and a slightly lower dose when you get good overlap again like that should prevent a recurrence, I would think. If it's liver training, I would expect you will have to stay at 3u or even go a bit higher to get back to good #s, and then you'll have to keep battling it out til his liver settles down. Either way, I'm sure you are up to the challenge!!! And it's really nice to see some greens for him!!!!!!!!!!!!!!!
[I'm starting to think of it as "useful rebound" (protecting body from actual true low # or steep drop that could lead to that) and "needless rebound" (liver training). Both being rebound, just with different causes (or "Rebound Without a Cause" :roll: I guess for liver training). And different treatments: useful = dose really is too high, useless = dose probably isn't too high (though reductions still could be needed on low PS or with awesome overlap in play). Not sure if all that is useful to anyone but me.
]
I love it!