Adventures with Fiasp –  there’s plenty to learn.

Following the variation in absorption I felt I was seeing in my last post I’ve since had a bit of a reason to pause for thought. I was adamant that it couldn’t be the site where my cannula was, as I’d had no issues with Novorapid absorbing there. I rotate around my midriff such that a site gets re-used roughly every sixty days. Since I’ve been pumping, that would be about six times. I figured that shouldn’t be enough for damage. And yet…

The last week or so has been spent in an area on my lower back. If you think of my spine as 12, then the four sets I’d used have been placed roughly between 10 & 2. All of them have given me absorption problems in some shape or other, but in this time period, only using Fiasp. To be honest, it was a little stressful. I couldn’t see what was wrong and started to hypothesise. As my last post showed.

Then, a few days ago, after another couple of days of silliness, with hard to manage levels, I shorted the old set and put another new one in. At roughly 2 on the clock I mentioned earlier. And it’s worked marvellously. To the extent that with eating fast carbs last night and using a normal Fiasp IC ratio, I ended up where I wanted to (Easter eggs are bad….).

So what can I read into this?

Well the thing that’s most notable about the new site compared to those between 10-2 that I previously mentioned, is that there is a greater amount of subcutaneous fat than in those areas. Now I’m not a fat bloke, but small love handles sometimes can’t be helped.

So on me, does the amount of SC fat locally to the cannula affect absorption? It looks that way, but I put my hands up to not fully understanding how the added B3 in Fiasp makes it absorb more quickly, and perhaps that’s key to difference. However, as we approached 3 days on the same cannula as the above picture, with a similar meal carb load, this was the result I got.

Even timing is similar and yet I’ve seen two rather different reactions.

So what am I taking away from this?

So far, I’m not getting consistent, outcomes from this insulin on sites I thought were good. When it works, it’s  brilliant but it’s much tougher when it won’t. That can make managing life much more challenging. Discussions with various people on social media suggests that some people have reduced their set change to once every two days as a result of loss of absorption using Fiasp. It’s not abundantly clear what’s going on, so there does seem to be a requirement to do some more testing. I’ve removed the risk of the insulin in the reservoir denaturing by reverting to 3 days use of reservoir and tube, so this leads to a suspicion of sites.

Given this hypothesis, I feel that an experiment is in order to determine whether there really is variation across the three days of site use, so in my usual n=1 fashion, after my next set change, I intend to do a fasted ISF test on the mornings of the three following days and see if I see any difference in the outcomes. It may yet prove to be inconclusive, but unless tested, I simply won’t know.

Footnote: If you’re a Fiasp user, I’m trying to collect together user experiences so that they can be shared with those who are interested. You can find the submission form here. The responses so far can be found by following this link.