Caffeine against persistent fatigue in long-COVID: a randomized clinical trial, 2025, Cardoso

I suffered serious addiction to amphetamine in my 20s, so I suspect that any kind of amphetamine would have a similar effect. I certainly wouldn't risk it, although I did try it after I kicked the habit, and I suffered the usual after-effects ('comedown'). I wasn't tempted to restart.

 

My understanding is that caffeine reduces iron absorption?

 

Wheneve I see any study about the effects of caffeine I wonder about differences in how people metabolize caffeine. Hasn't the impact of caffeine been shown to depend on several genetic factors?

I'm pretty sure I'm one of those folks who is a fast metabolizer of caffeine. I remember in college drinking coffee so I could stay up and study. But then I'd fall asleep really quickly. Caffeine has never bothered my sleep.

Even after ME/CFS the caffeine in either tea or coffee (although it's almost always coffee for me) does not bother my sleep.

I remember doing an experiment early on. I went on a diet without any sugar, caffeine or gluten for 6 months. I actually extended the experiment to 8 months because I kept hoping that some sort of diet change would help me. But there was absolutely no difference in any of my symptoms, including how well I slept.

 

Or PEM afterwards. It's rather meaningless to boost the distance if the increased distance triggered PEM.

 

Caffeine didn't make any difference when I was sicker. Ephedrine had some effect though. But caffeine also started to have some effect, particularly for the afternoon crashes, since I moved to the mild side of the spectrum. Neither raises the PEM threshold, I don't think. But they do moderate the PEM for me.

 

I have a feeling that caffeine doesn't affect my sleep either. I have cocoa in the early evening instead of coffee, but that also contains caffeine.

It's other things that affect my sleep, notably PEM.

 

Yes, PEM makes my sleep much worse - no trouble falling asleep, but I don't sleep well, and I wake up many times during the night.

 

which is a cursed vicious cycle, when poor sleep causes PEM…

 

I’m on five sleeping meds at the same time because of that!

 

I see what they’ve done

it’s the old separation as a collection of symptoms ‘fatigue in’ then measure it as a short term phenomenon

except for me/cfs we all at various levels of severity did this short-term experiment

it’s the difference of saying paracetamol is a treatment for a broken leg because it makes it more walkable on for the few hours after you’ve taken it

yet the same people hand waiving to suggest it (if we are metaphoring to me/cfs and the expectation we should just keep meeting our obligations) then criticise when more and more is needed for the same effect as the person and the leg gets more damaged and exhausted as a result of being expected to just ‘use this fix for the pain and get on with it as if that’s the one issue’

this is reframing basically


But it is important if someone was doing this for the right reasons and was noting the raw data intricately so those running future trials had to heed the impacts of this and control for it

you wonder how many studies suddenly put strong coffee in the waiting room when patients who’d done a course if whatever came back to fill in their ‘after’ questionnaire or task

with chakder fatigue questions about sleepiness or how tired you feel or slips of tongue