More info about PEG in the COVID vaccines - Allergic to Glycols

Allergic to Glycols

More info about PEG in the COVID vaccines



Relevant info:

The Food & Drug Administration (FDA)

Fact sheets provided by the FDA for the Pfizer-BioNTech and Moderna vaccines state that you should not get the vaccine if you have had a severe allergic reaction to any ingredient in the vaccine, or if you had a severe allergic reaction after a previous dose of the vaccine. The vaccine requires two doses given three weeks apart (Pfizer) and four weeks apart (Moderna).

Here are the ingredients in the Pfizer vaccine:


Lipids ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3- phosphocholine, and cholesterol)

Potassium chloride

Monobasic potassium phosphate

Sodium chloride

Dibasic sodium phosphate dihydrate


Here are the ingredients in the Moderna vaccine:

Messenger ribonucleic acid (mRNA)

Lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG], cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC])


Tromethamine hydrochloride

Acetic acid

Sodium acetate


6 Replies

I looked up ingredients of the Astorzeneca COVID vaccine and the website I looked ( at said it doesn't contain PEG but contains polysorbate 80 and that people with a PEG allergy would be fine with it . My understanding is that its related to PEG - has anyone had experience with a reaction to polysorbate? I'm concerned having a vaccine will be mandated for my job. Thanks

gothchiq in reply to Debduck

I personally haven't reacted to polysorbate yet but I know it is related and many people do react.

Unfortunately I am very sensitive to Peg and have had severe allergig reactions. I am also sensitive to all Polysorbates. I would be very careful and I can't be taking the vaccine. My hope goes to other vaccines.

Thanks for replying! One of the allergists I've spoken said to watch out for polysorbate 80 but I'm not sure about other polysorbates.

I have multiple allergies and have had anaphylaxis to sulfa and clindamycin. Reactions to both flu and pneumonia vaccines. Had first dose of Moderna Monday morning. 2 Epipens, 40mg prednisone IM, 50 mg benadryl, asthma rescue inhaler. Now on prednisone for a few days. My allergist wants me to find products that do not have polyethylene glycol or polysorbate since they are "chemical cousins". I'm having a hard time finding benadryl (diphenhydramine) without it. Any tips would be greatly appreciated. FYI - Children's Zyrtec does not have glycols.

gothchiq in reply to labelreader

The one I use is by SDA Laboratories and is available on Amazon. Dipenhydramine HCL capsules, USP, 50 mg.