Since news in December that government officials and developers had successfully shepherded the two vaccines through FDA authorization, it’s been all-hands-on-deck around the country (including right here at Forward) to get both vaccines off their respective production lines and into people’s arms.

Still, as we all wait for our turn to get our two shots according to our different state and local governments’ phased approach, it’s perfectly natural to wonder, “What are the COVID vaccine ingredients?”, and “Are they safe to take?” Well, we took a look at both Pfizer-BioNTech and Moderna’s publicly available ingredients list in order to find out what everything is in the order they’re listed, and here’s what we found.

Pfizer-BioNTech COVID Vaccine Ingredients

  1. Messenger ribonucleic acid (mRNA): If DNA is the recipe book cells within all living organisms use to reproduce themselves, then mRNA is like a copy of the recipe used to actually start cooking. In the Pfizer-BioNTech vaccine, viral mRNA, as opposed to live virus or inactivated virus, is its main active ingredient. And the role of that mRNA is to provide instructions, i.e., the recipe, for our cells to produce copies of a specific coronavirus protein that triggers our immune system to train itself to fight back if the real virus ever shows up — all while the mRNA itself remains perfectly harmless.
  1. 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),: According to the journal Nature, lipids, a class of fatty acids which when combined together with other lipids to form lipid nanoparticles (thus all the long hard-to-pronounce chemical-y sounding names), act like little delivery vehicles into your body for nucleic acids like mRNA, helping to make the vaccine more effective. 
  1. Potassium chloride: A type of salt, potassium chloride is used to maintain the pH balance of the vaccine. 
  1. Monobasic potassium phosphate: Another type of salt.
  1. Sodium chloride: Another type of salt.
  1. Dibasic sodium phosphate dihydrate: Another type of salt.
  1. Sucrose: A type of sugar, sucrose is added to vaccines in order to keep them stable.

Moderna COVID Vaccine Ingredients

  1. Messenger ribonucleic acid (mRNA): Moderna’s synthetic mRNA have the same therapeutic function as Pfizer-BioNTech’s, with both vaccines targeting coronavirus spike proteins in order to train the body to produce an immune response.
  1. Lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG], cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]): Moderna’s lipid nanoparticles effectively work in the same fashion as Pfizer-BioNTech’s, however Moderna has opted for a different mix of synthetic lipids. 
  1. Tromethamine: Similar to the salts in the Pfizer-BioNTech vaccine, tromethamine is a type of alkaline buffer that, along with tromethamine hydrochloride, helps maintain the pH balance of the vaccine dose.
  1. Tromethamine hydrochloride: See above. Tromethamine hydrochloride needs to be mixed with tromethamine in order for the combination to reach the right pH of between 7 and 9.
  1. Acetic acid: If the tromethamines are the base, then acetic acid is — you guessed it — the acid that also helps maintain the vaccine’s pH balance.
  1. Sodium acetate: A salt for maintaining pH balance.
  1. Sucrose: A sugar to help keep the vaccine solution stabilized.

If you’re wondering if the ingredients listed above in both Pfizer-BioNTech and Moderna vaccines are safe to take, the answer is “yes”; both vaccines, for instance, were authorized by the Food and Drug Administration as safe and effective, and California state health officials have even come out to say that neither vaccine includes ingredients that they would deem “out of the ordinary.” In fact, our doctors at Forward have received the vaccine and believe it is safe for almost all members.

That said, as with any vaccine, there remains the chance of side effects. In the case of these two vaccines, side effects can mimic some of the milder symptoms of COVID itself. But if you weigh those side effects against actually contracting COVID, the dangers are minimal by comparison.
If you’re wondering about how and when you can get your COVID vaccine, keep checking Forward’s Vaccine Updates page for the latest information.


No long waits. No surprise bills. No copays — ever.

Fed up with a soul-sucking healthcare system? Same. With unlimited visits, personalized insights and real, actionable results, find out what it’s like to actually enjoy seeing your doctor.