Thyroid, Histamine and Quercetin

Hi all, 

Has anyone had any experience of treating histamine issues with quercetin while having an underactive thyroid? 

I have checked through this forum, Thyroid UK, Stop The Thyroid Madness websites and many other sources but not come up with much, but there are definite links between thyroid and histamine.  

I have researched hypothyroidism and using quercetin and some sources state it has a negative impact, due to being a flavanoid  (aren't flavanoids in fruit and veg??)

However I am a believer in anecdotal evidence, so just wondered if anyone with hypothyroidism uses quercetin for histamine issues, and successfully with no thyroid problems?


11 Replies

Yes, there is most definitely a link between histamine issues and hypothyroidism. I suggest going to the Allergy UK forum. I haven't been there for quite a while, but I know there was quite a bit of discussion about this a few years back. Just type thyroid in the search box at the very top right of this page


It depends on what you read. 

Many hypothyroid members have mentioned allergies and high histamine responses//intolerance. ... possibly initiated and perpetuated by the sharpened over active immune responses to Hashimotos ? ? ..) .. 

Quercetin is in fruit & veg but if you were wanting theraputic doses you would need to supplement. I have read that quercetin can interfere with thyroid activity but you won't know without trying. 

Alpha lipoic acid has exactly the same cautions but was recommended by my endo and it appears to have interfered in a positive way. It is to do with methylation and how we utilise and detoxify. If you have MTHFR issues and suffer allergies, it is worth avoiding fermented foods. 

A lot of my allergy issues (post nasal drip, etc) stopped when thyroid meds got optimal and worked properly. Supplementing Curcumin dampened by immune responses but I still get hissy ears & sneezing after alcohol so hardly drink now.

I use quercetin, which seems to be helpful, but not on its own.  I still take antihistamines, especially if I am going to be having alcohol, which is a major trigger for me.   I have found zinc very  helpful as well.   My plasma zinc levels are very low, despite supplementing, so I take quite a high dose now (around 50-55 mg per day), which is usually not recommended for long periods.  Vitamin C is also helpful.  

You may  have already read this book, but if not, I would highly recommend it: 

"What HIT me?  Living with Histamine Intolerance... " by Genny Masterman. 


Interesting that alcohol is your trigger & I too had zinc deficiency so supplement 25mg daily & 3g Vit C.

I haven't read the book so will get it. 

Thank you 

radd, yes, I found zinc helped me a lot.  The following article is interesting.

If you do a search on zinc and allergies, you will find a lot, especially on the relationship between zinc and asthma. My histamine response is always respiratory - sneezing, stuffy nose, difficulty breathing.  

Maybe you should have your plasma zinc tested and see if you're still deficient.  I found I was still deficient on 40 mg supplementation per day.  

I also found that reducing the histamine rich foods in my diet has helped, though it's difficult to stick to that long term. 

I also take 3 g vitamin C.   That seems to be a good dose.  Sometimes I take a bit more (if I'm going to have alcohol!)

Thanks all for your responses. 

Radd,  you sound a bit like me with the allergies which have been lifelong for me.  The hissy ears with drinking struck a cord with me, and I even go a bit deaf, as well as very flushed, especially with wine and champagne, a classic histamine response. And post nasal drip has been my life for 40 years! Along with a multitude of other allergies since childhood. 

I've suspected recently that I have histamine intolerance (after discovering it quite accidentally) and think it's having an impact on my thyroid, and vice versa, a kind of vicious cycle really. I've ordered the DAO replacement enzyme and I'm waiting for it to arrive, so I'll see how I get on with that, and I've switched my probiotics to the type that helps clear histamine. I have a multitude of digestive issues including coeliac disease, so it wouldn't surprise me at all to have a low or missing enzyme. I'm also going to try vitamin C in therapeutic dosages. I'll try all these treatments one at a time so that I know whether I have a good or bad reaction, or none at all. 

All this is what has lead me to ask about Quercetin on this forum, it's something I can also try instead of OTC antihistamines and I've read that it can regulate mast cells as well, which also helps with histamine intolerance. However I'm cautious due to its potential impact on my thyroid. I've had quite enough of my thyroid not behaving over the last couple of years so I shall wait and see with that one. 

As you can see I've done my research and have got the book suggested on the way too (I'd already earmarked it online). 

I've been on a real journey with my health for some time now and have seen no end in sight, and the NHS just want to prescribe a pill for every ill or refuse to recognise obvious issues and gaps in health care. The whole histamine intolerance thing just seems to really make sense to me and I wouldn't be surprised if I've always had it. I'll just have to wait and see what happens with my experiments. 

My doctor is actually very good and I always tell her what I'm doing and she monitors me alongside her conventional treatment, she's just bound by the narrow and sometimes archaic rules of the NHS.  

I'll report back with the results of each thing I try, at least maybe that way it can help others who don't know which way to turn next, people who just want to feel well, and normal, again. 

May I ask which probiotics you switched to - to help clear histamine ?

I was using Optibac anyway, the everyday ones plus everyday extra, but then I read that some good bacteria help clear histamine and some encourage it, so I stopped the extra ones and switched to daily immunity, they have 2 of the 3 recommended bacteria. The cholesterol ones have the 3rd bacteria but none of these probiotics are cheap so I'm just sticking to the 2 types for now. Seems to be working well. Optibac are good because they don't need refrigeration.

PS I have just been reading a well renowned and highly thought of thyroid book, and they actually recommend taking quercetin for underactive thyroid! So that's great news for me as it could have a double positive effect for me. They also recommend supplementing with certain vitamins and in certain amounts, so I'm just building that up, and then I'll start the quercetin. I'm struggling a bit with vitamin A though, my digestive system really doesn't like it, it's quite common apparently as it difficult to digest like that, even if taking it with fat. I'm waiting for a different type to arrive, if that doesn't help then there is a sublingual liquid version available. This book is definitely the best I've ever read on the subject. It's no nonsense and to the point, and gives excellent active advice on how to help yourself rather than simply relying on doctors and thyroxine alone. It's called Thyroid Power and I bought a used version from a well known online retailer 😉

I'll report back once I've taken the vitamins for a while to see if I feel better. It's the fatigue and low mood that impacts me the most. I feel like I've already benefitted from taking high doses of vitamin C throughout the day, does help with energy a bit, and in the long term it's supposed to help with the Thyroid. (Start slowly with vitamin c and build up to bowel tolerance levels, I take chewable vit c which is much easier). Got nothing to lose by taking some vitamins eh? I don't mind popping a few extra pills everyday if I get to feel better. I see it as concentrated food, and Thyroid people can be lacking because we absorb less, and I absorb even less as I have gluten intolerance issues as well as IBS and low stomach acid, and this can all be linked to Thyroid too. It doesn't replace a healthy diet of course, and my breakfasts are key for me. Good luck to whoever reads this!

How are you feeling now? And what has worked best for you?

I have MANY of the same health issues as you, plus more. I'm very interested in your progress and always looking for clues and ways to improve.


I am having similar issues. Allergies for years, now thyroid problems. Recently started synthroid medication, which actually helped my allergies , but I now have other symptoms and I just don't feel well. Looking for an alternative to help me feel normal again.

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