Quercetin - how long does it take for it to work?

Recently I kept up my one a day quercitn when I ditched everything else. I seem to think its helpful related to sort of daily cycles of swelling/angiodema type stuff.

This suggests I think it might be sort of helpful like an antihistamine might be (only I don' take those, scared of drying effects).


Senior Member
Great Lakes
I've never had it work right away for me like that and from things I've read it does take time for the effects to build up unfortunately.

Some things we found that worked quickly for my Mom's allergies were things like:

-low dose b6 + zinc OR
-infantis probiotic, OR
-nettle and brigham tea.

Usually, w/in 5-10 minutes after taking one of those combos or things, her nose would start to dry up.

I think the first two help with histamine and the body's production of Daosin.

I think we figured out the nettle and brigham because nettle is suppose to be good for seasonal allergies and brigham is natural sudafed so like a natural antihistamine + a natural decongestant.

Because they've made otc sudafed harder to get many manufacturers like Nature's Way also discontinued marketing brigham but you can still find it in places like ebay. We bought a big bag of the branches there and I would just stick a twig in hot water and let it steep for about 5 minutes before she would sip it.

Of course, be careful if you are on prescription medications as it can be difficult to know what the interactions would be. Also nettle is high in vitamin K1. There are warnings about K1 and prescription blood thinners.

Additionally, my Mom was super sensitive to things just like I am so usually only a pinch of things (or maybe 1/5 of a tablet of things) worked for her.

One more warning: sudafed is a stimulant so I would assume brigham would be also since it contains ephedra.


Senior Member
I take quercetin daily for MCAS and as an antioxidant. The idea is to have it continually available for the body to use, not as response to an acute incident. For that, I use Benadryl.
This is exactly the same for me except in an acute incident, I use Atarax vs. Benadryl (b/c it just works better in my personal case).

Jennifer J

Senior Member
Southern California
Thank you everyone for your responses. I'm still unclear how many days or weeks does it take to build up in your system so you see the affect of it? How long does it take for it to work? Thank you if you have some idea.