Foggyness after drinking Soylent?


It seems every time I start drinking Soylent, within 5-10 minutes I start to feel this sort of foggyness that hits my brain, and it seems to last for a long time…at least 4-6 hours from what I can tell. It’s pretty uncomfortable and makes it very difficult to focus, so I’d really like to see if I can figure out what it is that’s causing this issue.

Has anybody else experienced this? It almost feels like I might be allergic to something in Soylent, because it starts to affect me so quickly.


How long have you been eating Soylent? And how many of your meals do you use Soylent for?

There was someone else who experienced something similar. I think there was a specific ingredient singled out as the culprit.


I’ve heard that some people experience this, but it may be placebo because 5-10 minutes is pretty damn quick. I takes at least a half hour for almost anything to be digested and absorbed into your body, some things can take an hour or two to have any effect. Cannabis edibles take anywhere from 45-120 minutes to “kick in”, I know Claritan D (allergy medication) takes about a good hour to kick in, even liquid things such as cough syrup take a good 30 minutes to kick in, even on an empty stomach.


Are you sure it’s not postprandial somnolence? That’s typical after a large meal, more pronounced for some people than others. How much Soylent are you having at once?


Thanks for the replies.

@livingparadox - I’ve only consumed Soylent about 5 different times since I’ve received my shipment about a week ago. My intent was to consume about one meal’s worth per day (usually for lunch) and occasionally for breakfast or dinner as necessary. But since I’ve been experiencing this foggyness, it’s made me reluctant to get on a real schedule with it because I don’t like feeling like this at work.

Do you remember who it was that experienced this problem or what the ingredient might have been?

@brando56894 - I agree, it doesn’t make much sense because it seems to happen ridiculously quick. I can tell you I’ve always had a very fast metabolism and it’s not uncommon for me to be hungry only 2 hours after I’ve had a meal. But 5-10 minutes still seems very odd, I agree.

@asympt - I’m pretty sure it’s not that, because I do also get very tired after large meals and after a full meal of Soylent, so I know how that feels as well. Plus, this effect starts to happen very quickly…I’ve had a full meal’s worth of Soylent (1/3 of a bag) 3 different times, and I’ve had a “snack” portion twice. The snack portion definitely doesn’t make me as tired, but I still get the foggyness almost immediatley after I start drinking.


Unfortunately no, and I can’t seem to figure out how to find the thread through search. If I find it, I’ll link to it.


You can search for “fog” on the main forum page, and several posts appear. Be sure to click on show more at the bottom to see them all.

I remembered reading about brain fog in this article

He doesn’t go into what causes it though, but it apparently cleared up on day 3. Also, these articles were using pre-1.0.


I know that I experience a kind of dull, distracting headache when I start using soylent after a break, and it’s because of the potassium.

I know this because I made a mistake in my DIY, and for a long time, I was getting 50% of the daily value for potassium. I found my error and fixed it, so suddenly I started getting 100% of the daily value of potassium… and got headaches for two days. They were gone by the third day.

It’s also easy to lose track of how “quickly” the headache comes… You may feel it ten minutes after finishing the drink, but if you take twenty minutes to drink it, you’ve been consuming for half an hour - and many things are more easily absorbed in a liquid diet.