Adverse Reaction to first drink of Soylent?!?


I got my Soylent yesterday and couldn’t wait to switch over to a 100% Soylent diet. So, after eating my normal breakfast and lunch I mixed up a pouch of Soylent. At about 6pm I was hungry and so I drank about 2 cups worth. It was yummy and I was so happy. Then about an hour or two later I started to get a headache- not unusual for me. I just drank some water and took a couple ibuprofen. Then I started to feel hunger pains and a little weird. I felt light headed and jittery. I was seeing trails in the light and just felt off. I though I was getting a migraine. I was vaguely nauseated. I decided that I needed to eat something because the hunger pains were still there. I ate an apple and some crackers. While eating I felt much better, but the sick feeling returned. I slept okay and wanted to drink some more this morning, but I had a hangover type feeling. I ate my regular breakfast but added in some Soylent. I’ve felt weird all day but not as bad as last night. I almost felt like it was a reaction to the Niacin, I felt a little flushed. But my cereal has almost the same amount. Has anyone come close to this reaction? Did you power through? I’ve had weird reactions to stuff before. Five hour energy puts me to sleep. I’d really like to figure this out, thanks!


It makes me wonder if you are allergic to something in it.


Wow… can’t say I’ve heard of anything like that so far from anyone! If 5 hour energy puts you to sleep, it does sound like you’ve got an unusual metabolism in some way. Maybe there is something in Soylent that doesn’t happen to agree with your physiology. Boy that’s a bummer if so… but maybe someone more versed in these things can chime in with something helpful. =(

Do you know yourself to have allergies to any particular types of foods or anything else?


A number of people have been discussing headaches from drinking Soylent here:

I actually experienced something similar for a while with my DIY soylent, and eventually found that the biggest culprit was the masa harina I was using - I’m guessing it’s an intolerance to some of the preservatives used, as I’m usually fine with corn. However, I also experienced a similar (but milder) reaction to the GNC Mega Men Sport powder, which contains vanillin and sucralose just like Soylent. Then I experienced the same sort of thing with official Soylent, so I’m wondering if it might be one of those additives…


I had a bit of an ‘off’ feeling at first too, which could have been related to switching over to Soylent - but as I’ve mentioned elsewhere, I ended up catching a virus at the same time I started, so all my experiential data is contaminated and unreliable… :angry:

In any case, anything I can guess at attributing to the Soylent was certainly not as strong as what you described. A few people have suggested easing into it, with only one Soylent meal per day at first. Maybe try that, and let us know how you feel over a week or so?


I had a similar reaction when starting in on People Chow several months back. I went back to normal food for a bit and then tried just replacing a meal or two on People Chow and didn’t have any issues.

I don’t know if it was a virus or just getting adjusted over onto the new diet. I’d recommend going normal food for a day or two and when you’re feeling solid try replacing one meal a day at first.


Some people mentioned that potasium can have that effect if you were deficient before starting… And you will feel like that until your body adjusts… But idk, try easing into it… Or maybe eat normal for a week and then try again?

Or maybe actually you might be allergic to either vanillin or sucralose… Soylent needs to get rid of those two things if some people are truely allergic to it.


I experience very similar symptoms to OP, except I NEVER had headaches until Soylent. The funny thing is I was on DIY which was based on masa harina for 4 months and I’ve had 0 problems on it. With the gas and head problems on Soylent I actually went back to using DIY for breakfast and lunch and am using Soylent for dinner hoping that my body needs to adjust to something in it.


Thanks for the input, I may be allergic/sensitive to something in it. I think the consensus here that I should try slowly adjusting to the soylent. I did have about a cup’s worth throughout today and feel a little better than I did after downing 2 cups last night. Thanks for the thread about headaches, that wasn’t a main concern, but it’s good to know other people are having a reaction that isn’t about gas. :smile:


I think Soylent has a fair amount of easy to digest carbohydrates, so I wonder if the quantity that you drank was too much all at once which would especially be a concern for anyone that would be borderline diabetic. I tend to sip it over a much longer period of time when possible. I know I can feel similar symptoms if I OD on sugars. The hunger pains following would be a classic sugar crash affect. I also prefer to drink water after my meal, to help with digestion. Just some ideas that may or may not apply to you.


I suspect this may be the culprit. My blood sugar spikes quite a bit higher (and faster) than it does on normal food when consuming Soylent. Only ingesting a small amount at a time essentially eliminates this effect. This is something @vanclute has been suggesting from the beginning and that I, in all my wisdom, ignored until I was able to pinpoint the culprit.

Some people (namely me) never learn…


LOL Human beings only truly learn one way - by making mistakes. Even then some don’t learn, but you apparently aren’t one of those. :wink:

And really it seems quite individual anyway. Some people do just fine drinking large portions at a time. I think everyone just needs to identify their own best use for Soylent, but I still think starting slowly is probably the wisest to avoid any potential discomfort.


I’m cautiously optimistic to report that the slow ingestion of Soylent seems to be working. I ate regular food yesterday and about a cup of Soylent. Today, I’ve had about two cups over the morning/afternoon with no regular food and so far so good! If it was an allergic reaction, I think I’d be experiencing it again. It may be as a friend suggested that my body was in shock by the quality of substance I was consuming as opposed to the junk I normally give it.


Reminds me of the Jim Jupiter episode of Married With Children, but in reverse! (apologies to those for whom this reference is meaningless ;))


I, too, have been getting some weirdly low/blunt headaches, as well as tracers/stars in my vision this morning since switching to a mostly-Soylent diet about 48 hours ago. I was reluctant to assign them to Soylent but the headaches seem to begin about 2-3 hours after ingestion. (I am making a point of staying adequately hydrated.)

I’m going to give it another couple days and see if it gets better or worse. If it gets worse I fear I might have to stop eating Soylent. :confused:


Let us know where you end up, either way… I’m still trying to figure that out for myself, too.

If it doesn’t work out at least you can eBay off your remaining stash of Soylent. :wink:


So I actually had this same reaction (the stars & light-headedness & such) when I went on a pretty strenuous mountain bike ride one afternoon, and hadn’t really “topped up my tank” first. I took a break and had some more Soylent and it passed. It sounds like this is a case of just not being fed enough, or possibly dehydration. Should be pretty easy to “fix” if so.

One thing that I think is different about Soylent is that, because it’s so balanced… when you’re undernourished your body “fails” in a very different way than if you just don’t have quite enough sugar, or carbs, or protein, etc. It’s like an across-the-board systems failure, all at once. And it’s a very VERY strange feeling.

Nothing to back this up of course other than my own experience and what I’m reading from others here… but it’s what seems to be the case from my POV.


while that is a very vague analysis, it makes perfect sense… lol

i also am having mild headaches…keep track of it myself.


Sounds like a migraine, actually. (Right down to the ‘hangover’). Whenever you introduce a new food to your diet, particularly if you do so in a large quantity, you upset your intestinal flora. Some grow prolifically, while others die off. Since so much of your immune system and hormonal systems are tired to your intestinal flora, it’s no wonder that this cause widespread bodily discomfort. It would be the same with any extreme change in diet. Migraines are a common reaction to sudden diet changes. My advice would be to start slow, and continue to eat your regular diet. Gradually increase the amount of Soylent, and decrease the other foods, over the course of a couple of weeks, if you’re prone to these types of reactions. (The same advice is given to folks who switch pet food brands for dogs and cats, and for the same reason!)


By the way, I’ve been looking at other Soylent ingredients, and it seems more likely that Gum Arabic could be causing the gas, rather than the vanillin or sucralose. It’s a form of fiber that might be a surprise to your intestinal flora. :stuck_out_tongue:

I’m going to see if I can get my hands on some and taste it. :wink: