Please stop using Cyanocobalamin Vit B12

Placed my first order today and will give it a try but I was disappointed upon checking the ingredients list to see that the vitamin B12 is delivered as Cyanocobalamin. This is linked to cyanide, yes cyanide, and can cause some bad reactions in some people - from Wikipedia -

The oral use of cyanocobalamin may lead to skin problems or immunological reactions such as itching and anaphylactic shock.[10] Possible side effects of cyanocobalamin injection include several allergic reactions such as hives, difficult breathing; redness of the face; swelling of the arms, hands, feet, ankles or lower legs; extreme thirst; diarrhea. Less-serious side effects may include headache, dizziness, leg pain, itching, or rash.[11]

There is plenty more info out there about Cyanocobalamin if anyone wants to take a look. I’m aware a lot of these things are internet over reactions and scares but in this case I’ve experienced the effects myself. Please stop using it.

Comments noted and we will bear this in mind.

However, I’m cautious when linking single nutrients to reactions as there are many confounding factors


It certainly doesn’t affect everyone and I’m sure most people won’t have any issues, but from my understanding of your aims, you want to go for something completely neutral in terms of allergens and food intolerances.

Perhaps strangely, this ingredient is the one thing I know I’m allergic to or have reactions to. I’m generally tolerant of everything else so it’s odd that I should struggle with this.

I believe methylcobalamin is considered a preferable alternative and might be worth looking at. Not sure about the trustworthiness of this site but it’s one I found that talks about the differences.

I don’t know anything about that ingredient but that website, naturalnews, is well-known for publishing lies and total nonsense


Regarding the “link to cyanide”. Table salt is a compound of sodium and chlorine. Both of which would kill you double quick. It doesn’t mean salt will. Chemistry doesn’t work like that.


That website does indeed seem untrustworthy. It was just the first I found after a quick search, there are others with similar info.

I’m aware there is no actual cyanide involved despite the hyperbolic nature of some of the sites that talk about it. However, it is still an ingredient that I’ve had trouble with in the past for whatever reason and I’m not allergic to anything else as far as I’m aware so in my experience there’s something about it that may cause issues.

I just think that for a promising product that I was otherwise interested in, it would be good if this one potential downside (for me, maybe others) could be eliminated. That might be a little idealistic but there you go.

1 Like

The amount of cyanide in 1,000 micrograms of cyanocobalamin is about .6% of the amount that is thought to be the lower level that causes harm. Huel, if I read the nutrition label correctly, provides 4.5 micrograms of cyanocobalamin per day.

Without doing the research, I’d venture that you get more cyanide from fruits, nuts and seeds.

All that being said, maybe Huel can decrease the amount of Vitamin B12 from 4.5 micrograms to 2.4 micrograms (the RDI).


I’ll second that. That website is a terrible publication. I’ve had the displeasure of reading some of their “news articles” and finding they don’t do journalism or honest research in any way, shape or form.

Their redeeming feature is that they add links to news sources, so that you can easily see they actively change the text others wrote to suit their editorial criteria and “pharma is evil!” agenda.


Those are a mix of potential side effects from oral and intramuscular Cyanocobalamin supplementation from the extremely rare persons allergic to direct B12. (I forgot this bit on first post)

Which means, don’t drink Huel if you’re alergic to B12 supplementation!

Hydroxocobalamin (the precursor to Cyanocobalamin) is actually given to people for cyanide poisoning. source

“…mild [cyanide] toxicity is observed at [blood] concentrations of 0.5-1.0 μg/mL” source

Thats .5mcg of cyanide per millilitre of blood.

Someone with 5 litres of blood would need 2.5g (2,500,000 micrograms) of Cyanide in their blood stream to meet the criteria for mild cyanide toxicity!

“Taking 2mg [2000mcg] or less a day of vitamin B12 in supplements is unlikely to cause any harm.” source

There’s just too much of this fear-mongering pseudoscience bullshit on the internet.

Also, for your information:

“The rate of spontaneous detoxification of cyanide in humans is about 1 µg/kg body weight per minute…” - (Schultz et al., 1982)

This means that the Cyanide ions (2% of Cyanocobalamin = 0.18mcg) released by metabolising the 9mcg/100g of Cyanocobalamin (the cheapest source of B12), will be converted within 10.8 seconds (yes I actually did the maths!) into Thiocyanate and excreted through the urine.

Relax and Huel :slight_smile:


Yeah, before the internet we had to rely on the Daily Mail for our pseudoscience bullshit.


I ordered it recently as well and simply love it. I love the taste and it makes me feel good too.

However, I started having it on Monday morning and Monday evening when I returned from work I had a huge itchy rash on my back. Didn’t think much of it.

Tuesday morning I had another 3 scoops and Tuesday evening there was a rash on my stomach. Itchy as well.

I had it Wednesday morning and a new rash developed on my stomach.

I don’t think I am doing anything different other than eating Huel.

The rashes looked like they could be hives so I googled huel allergy and it led me to this page. The symptoms given above sound exactly like what I am having.

I don’t believe it’s cyanide obviously lol but there’s definitely something up and I don’t want this to be the end of my Huel journey.

I really see this as becoming a big part of my life but I don’t obviously want rashes all over. I’ve had it this morning as well as a final test. If something new develops I’ll have to stop it. :frowning:

I know I am not allergic to B12 supplements having had them in the past. But maybe this particular form of B12 doesn’t agree with me.

Ok, thanks for the (lack of) responses here but…

it seems that Huel may not have been the culprit and I did not have hives. I had the shingles which started exactly on the day of my starting Huel, hence the confusion.

Now almost fully recovered, I have started taking Huel again with no ill effects.


The only reactions I’ve had to Huel are sleeping better, more energy and improved body composition.


Ouch, nasty, get well soon

Hi @vseera
Sorry for the lack of response. Hope things are improving for you now.

Isn’t there cyanide in apple seeds?

Hi all,

I did two days of Huel (two meals/six scoops/day) yesterday and day before. I felt great, much more energy throughout the day, none of my usual 4pm crashes. But it brought me out in a pretty serious rash and made my face flush and itch like crazy. I avoided Huel last night and today and my skin is almost back to normal already. I had wondered whether it may have been the pea protein (which I am new to) that caused the allergic reaction, but this B12 thread has me wondering as the symptoms described (especially the facial redness described on wikipedia) exactly match my own. Any thoughts? It’d be a shame to have to stop using what could have been a game changer for my active life : (

I have been using Huel for short time and seen all positives mentioned, however have also noticed the redness of face and other effects mentioned here, and was previously not suffering from these. I hope it calms down (2 days in) as i dont want to stop using Huel.

I recently started Huel. The first time I had it, took 2 scoops, I had generalised rash and itch which looked like urticaria. I was disappointed and decided to stop. Because i am a medic, I decided to try it again, this time sitting next to the crash trolley at the hospital where I work. I only had one scoop this time. No rashes or itching. So, I have been on it a week, and no problem. One scoop at a time, but more often. Almost on a Huel only diet.

Ooh, almond flavour…