Headaches shortly after Huel

Been trying unsweetened gf huel on and off for 6 weeks now but I’m struggling.

I have not yet changed my regular diet and have just been adding one scoop of Huel a day to let my system get used to it.

Every time I have a huel I get a terrible headache, sometimes even before I’ve finished the shake. I do not normally get headaches and if I skip the huel I don’t get a headache.

I get on fine with the bars though.

I’ve search through all of the headache threads but couldn’t see a solution.

Does anyone have any ideas? I am very keen to use Huel and don’t really want to give it up.

It’s almost certainly due to water in intake. How much are you drinking each day?

From the Nutrition pages on fibre

Huel contains 128-132% (based on European v2.3 formula, varies between flavour/variety) of the recommended daily amount of fibre. The fibre in Huel is a mixture of soluble and insoluble forms all naturally supplied from the food ingredients, mainly from oats and flaxseed, and provides more than most modern solid diets. The high-fibre content of Huel helps to ensure the formation of normal, solid stools in healthy users.

Fibre acts like a sponge, so it’s important to consume lots of water when using Huel(19). The Huel formula has been designed to maintain optimum digestive system health. Moreover, you may well have heard about the beneficial soluble fibre in oats called beta-glucan; well, Huel is loaded with this cholesterol-lowering fibre; ideal for a healthy heart(20).


I’ve been drinking my normal amount which is probably around a litre a day, and since huelling an extra 500ml water per day, which I’ve been drinking after the huel. My usual diet doesn’t have much fibre. So it could be water related.

Can it really cause a bad head that quickly?

I’ll have to up my intake.

A litre a day really isn’t enough at all. You should be drinking at least 2 litres, more depending on activity level.

Try this. Take your weight in lbs, half it and the result is how many oz of water you should be drinking. You can divide the oz value by 33.8 to get litres.

So for me, 190lbs / 2 = 95oz.
95oz / 33.8 = 2.8 litres…which is about right as I am for 3 litres a day :slight_smile:


You sound like me mother, :yum: I’ve always drunk around those levels and have never had an issue.
I can see how Huel would require drinking more.
It’s the speed that the headaches kick in that amazed me, if it’s due to dehydration, it’s must only be in my stomach for 10 minutes before I’ve even finished the shake.

I’ll try it out with a lot more water over the next couple of weeks and report back.

If you were using the Vanilla, I might think it was due to the Splenda/sucralose in it. I have not had that effect with sucralose, but I definitely get very bad migraine headaches from aspartame/NutraSweet.

Are you certain you’re using u/u and not vanilla?

(Yes, I know, you said you were, but… just worth double checking.)

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Yep double checked and it’s definitely u/u gf.
And as I don’t drink tea or coffee I probably consume more sugar free drinks than most, with no noticeable effects.

I’ll come off the huel for a couple of days get myself really well hydrated and try again.

The whole minimum 2 litres thing is rubbish, water in take is closely connected to your activity level rather than “drink at least 2 litres”. But if you’re only drinking 1 litre a day I’d say the headaches are almost certainly dehydration.

You’re drinking the Huel and you’re body’s going “whoa, loads of fibre, get some water to it quick” and then your head hurts because you’re dehydrated. (probably something more sciency going on, but that works for me).

No need for that, just drink more water :slight_smile:

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It’s around a litre, I don’t measure what I drink exactly. I’m disabled so have low activity levels for sure and I’m small.
More water seems like the obvious thing to try at this point.

You could also try buying some electrolyte drops to add to your water. They help your body hydrate better, if you think you’re somehow just not absorbing enough of the water.

That’s a good idea, I’ll investigate.

Not trying to advertise, I have no affiliation with the company, but I’ve had good like with this one:

I generally add 35-45 drops to a quart/liter of water. Works very nicely.

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If you are getting a headache within 10 minutes of starting Huel, I doubt it’s dehydration. I just don’t think your body would react to a lack of water that quickly.

More than likely you’re sensitive to one of the ingredients?

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This is what I’m wondering. I’m gonna give the extra water a try. If it’s a reaction to an ingredient I guess I’ll have to give it up, or just use the bars. But I wanted to try everything before I quit the powder.

I’m gonna start from tomorrow and try to give it a week to see what happens.

Well for the past two days I have drunk 2 litres of water plus 1 scoop of Huel in 400ml water and am very pleased to say no headaches.

I am going to try 2 scoops of Huel from tomorrow and I’m guessing that means I shall have to up my water intake again too.

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Great news. I don’t think you’ll have to drink loads of water, but definitely keep an eye on it. I’m glad it was a simple solution :slight_smile: