Ingredients
- Vitamin C – has many immune boosting properties, but is distinctively beneficial for individuals with seasonal discomfort because of its ability to deactivate histamine.
- Quercetin Dihydrate – biologically active flavonoid antioxidant that is widely distributed in plants including oak trees, onions and tea; Quercetin has strong antioxidant activity and has been shown to support immune health by mediating the release of inflammatory compounds.
- Stinging Nettle (leaves) – Urtica dioica, is a plant that has been shown to balance immune response, specifically in the airways and nasal passages; it controls mast-cell degranulation, prostaglandin formation, and histamine action all contributing to a balanced inflammatory response.
- Bromelain (from pineapple) – proteolytic enzyme that aids in in the breakdown of large protein complexes, including antigenic compounds, and has been shown to enhance the absorption of quercetin; shown to reduce circulating allergenic protein complexes associated with hyper-immune sensitivity and seasonal discomfort.
- N-Acetyl-L-Cysteine – (NAC) helps reduce the viscosity of the mucus allowing for clearing of the airways and improved respiratory health.
Does Not Contain: Wheat, gluten, soy, animal or dairy products, fish, shellfish, peanuts, tree nuts, egg, artificial colors, artificial sweeteners or preservatives.
Supplement Facts
Serving Size: 2 Capsules
Servings Per Container: 60
Amount Per Serving
%Daily Value
Vitamin C
(as Ascorbic Acid USP))
(as Ascorbic Acid USP))
300 mg
333%
Quercetin Dihydrate
400 mg
Stinging Nettle (Leaves)
400 mg
Bromelain (2,400 GDU/g)
(from Pineapple)
(from Pineapple)
100 mg
N-Acetyl-L-Cysteine USP
50 mg
Other Ingredients: Natural Vegetable Capsules, Magnesium Stearate, Silicon Dioxide, and Stearic Acid.
How to use

Daily Use:
Take two (2) capsules per day
Optimal Use:
Take four (4) capsules per day, in divided doses
High Stress Use:
Take (6) capsules per day, in divided doses
How to Use:
Capsules can be taken with or without food. Contents may be removed from the capsule and taken by spoon immediately after mixing with a small amount of tepid water.Questions:
Safe over the age of 12, supplementation in children should be monitored by their pediatrician.
Yes, but pregnant or nursing mothers should always consult with their health professional before supplementing.
Can be taken at any time of the day
The Science
- Della Loggia R, Ragazzi E, Tubaro A, et al. Anti-inflammatory activity of benzopyrones that are inhibitors of cyco- and lipo-oxygenase. Pharmacol Res Commun 1988;20:91-94.
- Kim HP, Mani I, Iversen L, Ziboh VA. Effects of naturally-occurring flavonoids and bioflavonoids on epidermal cyclooxygenase and lipoxygenase from guinea pigs. Prostaglandins Leukot Essent Fatty Acids 1998; 58:17-24.
- Otsuka H, Inaba M, Fujikura T, Kunitomo M. Histochemical and functional characteristics of metachromatic cells in the nasal epithelium in allergic rhinitis: studies of nasal scrapings and their dispersed cells. J Allergy Clin Immunol 1995;96(4):528-36.
- Mittman P. Randomized, double-blind study of freeze-dried Urtica dioica in the treatment of allergic rhinitis. Planta Med 1990; 56:44-47.
- Obertreis, B. et al. Anti-inflammatory effect of Urtica dioica folia extract in comparison to caffeic malic acid. Arzneimittelforschung 1996; 46(1): 52-56.
- Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial. Urology 1999; 54(6): 960-3.
- Cichoke AJ. The Complete Book of Enzyme Therapy.(1999). Garden City Park, NY: Avery Publishing Group.
- Yim CY, et al. Use of N-acetyl cysteine to increase intracellular glutathione during the induction of antitumor responses by IL-2. J Immul 1994;152:5796-5805.
- Ziment, I. Acetylcysteine: a drug that is much more than a mucokinetic. Biomed Pharmacother 1988; 42(8):513-519.
- Millar, A.B. et.al. Effect of oral N-Acetyl Cysteine on mucus clearing. Br J Dis Chest 1985; 79: 262-266.
- Bland JS, Costarella L, Levin B, et al. Clinical Nutrition: A Functional Approach. Second Edition. (2004). Gig Harbor, WA: Institute of Functional Medicine.
- Johnston CS. The antihistamine action of ascorbic acid. Subcell Biochem 1996;25:189-213.
Lisa (verified purchase) –
I’ve been taking this for two months. I replaced a RX for Ketotifen that had to be compounded monthly, with this product . I had also taken plain quercetin in the past with poor results. I live with MCAS.
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Kulie Fintak (verified purchase) –
As I have MCAS (Mast Cell Activation Syndrome) as well as histamine intolerance, I struggle with a variety of symptoms ever since I was little (I couldn’t jog outside in cold weather because cold temp would trigger MCAS and I’d be covered in hives, can’t smell perfume because that will not only make me feel nauseated but also instantly make my skin itchy, etc.). Even though I’ve learned how to cope with this over the years, there are times when I just can’t handle the amount of histamines in my system due to chronic stress (emotional and physical). I’ve had 3 major anaphylactic shocks and almost died… For this reason, I had to carry Epipen at all times. This product literally saved my life! It’s been a month since I started taking it 3 times a day and I can feel the difference because I don’t get hives as often as I used to. And I can sleep better because I have less histamine in my system. I’ve tried many other similar products but this is by far the best one, at least for me for sure! Thank you, Dr. Osborne! I can’t thank you enough!!
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Rachel S. (verified purchase) –
I had really hoped this product would help me with a horrible cough I get this time of year. I usually take Zyrtec to fight it off, but I would much rather use something natural. I took it as directed 3 times a day for 1 week and saw little to no results with the cough. I understand it really works well for some people. Sadly I was not one of them. I had to stop taking it after 1 week due to the bowel distress I started having. I think it irritated my system. I would send it back for a refund if I could, but they don’t take back open products. If you try it, I wish you the best, but it didn’t work for me.
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Betsy Thompson –
Love this product! Worked great for my seasonal allergies.
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Celia (verified purchase) –
Great product, it really did the job for my runny, itchy eyes and nose.
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Audrey (verified purchase) –
We find it very helpful for treating our allergies!
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daniel (verified purchase) –
so far this product has worked very well
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Denise (verified purchase) –
Very easy to digest. This is my second order!
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Navageco (verified purchase) –
Just two of these guys before bed help my itchy skin! Thanks
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Geir Angeltveit (verified purchase) –
I bought this product for my daughter, she has taken alergi medisin for many years. I told here to try the Hist Assist.
After 2-3 weeks she was so much better, she would never thought that was possible. No more medisin!
Great produkt!
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Deb Flurkey (verified purchase) –
I always deal with pesky spring allergy symptoms, but this spring I didn’t want to have them acting up with the COVID19 pandemic danger. Hist Assist has prevented the rhinitis that happens every year along with inflamed eyes and itchy throat and ears. I feel just a little safer in that my nasal passages won’t be all hot and bothered as I stay indoors to help flatten the curve of the virus.
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Sue Blake (verified purchase) –
I used to wake up in the morning with a literal mountain of Kleenex next to my pillow. Now, I take 2 caps before bed and only need 1 or 2 tissues before the morning.
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Debbie Foster (verified purchase) –
While suffering from terrible allergies this year, I decided to give Hist Assist a try. I sure am glad I did as it definitely worked! So nice to have a safe, natural solution that works this well for allergies.
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Chuen (verified purchase) –
I have been taking this for about a month. Lately the pollen count is high. Every year during this time, I’m usually miserable. I would sneeze 4 or 5 times in a row and several times a day. I would have red watery eyes. A couple days ago, I only sneezed twice. And I didn’t sneeze any today. A little while ago when it was on sale I bought three more bottles.
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Tiffany Faires (verified purchase) –
Better than Zyrtec!!
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Mary (verified purchase) –
This is the first time I have ever tried this product. I was very impressed with it it took care of my itchy eyes and running nose. My bf also got some relief from his allergies.
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peter (verified purchase) –
great product! see a positive change
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Susan D. (verified purchase) –
I haven’t used this on a regular basis yet, but I have taken it on occasions when I’ve eaten food that has triggered congestion, and the congestion went away. Worked as I had hoped!
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Fred (verified purchase) –
I just recently started taking these products. Great results so far. Have not been diagnosed with allergies but have sinus issues typically early morning. Dr. Prescribed Fluticasone Propionate which I used once until I researched the side effects. Hist Assist & Ultra NAC have provided excellent results from day one.
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Penny Harvey (verified purchase) –
This product worked for me, I had relief without any stomach upset or side affects.
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Barbara (verified purchase) –
I have had a problem with hives for over 3 years and have used many allergy drugs. The Hist Assist has calmed them down and am so much less itchy and not having to take allergy drugs. I also sleep better because I’m not having intense itching at night. Thank you thank you, thank you.
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Barb W –
just stated it, but I am happy there is something natural to use instead of drugs.
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D Serafini (verified purchase) –
I use this in conjunction with another allergy asthma med at bedtime and an Advair inhaler.
Just today, the breezes coming thru the window were generating sneezes & congestion.
Took Hist Assist & went outdoors an hour later with NO allergy symptoms!
Thank you!
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Patricia Fleming (verified purchase) –
Works like magic
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Debbie Hurst (verified purchase) –
My husband constantly blew his nose, cleared his throat and more and so I had him try this as nothing else worked and we avoid OTC’s He was skeptical, but said he was noticing a difference so I bought more and it’s helping! He’s a histamine factory!
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Pat (verified purchase) –
Have not noticed any improvement in sinus/respiratory issues.
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Lezlie Jones (verified purchase) –
After dealing with allergies for over a month once the harvest began, I could not get them controlled even with allergy medications. Within 24 hours of taking hist assist as directed my allergies were non-existent and haven’t flared up since.
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D (verified purchase) –
Great for allergy issues
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Sally (verified purchase) –
I love this formula. I have side effects with the over the counter and prescribed drug options. Not with Hist Assist. So happy to find this product.
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b.b. (verified purchase) –
This has been a life saver for me, I use it when I have sinus problems and headaches. No longer have to take over the counter products and love that it is gluten free.
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PatriciaWright (verified purchase) –
I have such a hard time with Mast Cell Activation Syndrome, and histamine reactions.
Some get pretty serious, and I’ve ended up in the ER twice with severe anaphalaxis. The ER Dr told me at my last visit that I had already started to die. He warned me that anything I put in my body could kill me. Hist Assist has helped me so many times in calming down, or preventing a histamine reaction, and it works fast. Usually my symptoms will go away within 10-15 minutes. Can’t say enough good about it. I am so thankful for Hist Assist.
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Michelle (verified purchase) –
This product is great for my histamine issues with mcas, and it is the best price that I have found for the quality.
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Peter (verified purchase) –
Helps me with my allerhies!
Almost 200% relief ehen pollen hits me!
Three cheers
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Ali Kashi (verified purchase) –
I took the hist assist and stopped sneezing almost right away!
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