Preventing Post-Covid Vaccine Effects


ADVICE to combat possible flu-like side effects of the SARS-Cov-2 vaccine has focused on “hydrating with electrolytes”—starting the day before the vaccine appointment. That has raised the following questions—what are electrolytes, what can hydration do and why include these together?

Drinking extra fluids—waters, juices, herbal teas—can help boost blood circulation and the body’s general health to prepare for the vaccine’s jolt to the immune system. A specific reason is to counter mild fever that can be a common reaction to the vaccine—taking acetaminophen post-vaccination is also suggested. (Other post-vaccine side effects—in addition to local pain at the injection site: fatigue, chills, nausea, joint pain and headache.)

Supplemental electrolytes—potassium and magnesium but most of all sodium—help the body retain rather than excrete excess liquid, which is especially helpful following strenuous exercise and in humid, hot weather. Drinking too much plain water can result in hyponatremia—insufficient salt in the blood—as can dehydration; and both can trigger muscle cramping and fainting. Medical rehydration formulas—usually salt and carbohydrates, or simple sugar —work by improving the body’s absorption of replacement liquids.

Electrolytes—calcium, phosphorus, chloride and bicarbonate, along with the first three—are minerals with an electrical charge that regulate cell function, help produce energy and stimulate nerve signaling and muscle contraction. Sodium in particular facilitates the contraction of heart muscles—aided by potassium, which is also credited for lowering blood pressure and decreasing risk of stroke, and is notable for reducing the risk of muscle cramps.

The concentration of electrolytes in bodily fluids like blood can vary only within a tight range without creating serious health problems. In addition to exercise and hot weather, illness accompanied by diarrhea or vomiting can disrupt the fine balance.

In research on pre-exercise hydration, salty chicken noodle soup produced the greatest retention of fluids, followed by a “carbohydrate-electrolyte beverage,” with water alone the least effective. And the desired goal of plasma osmolality (the amount of water retained in the blood) increased the most successfully after ingestion of the soup and “remained elevated throughout exercise,” as did proportionally reduced urinary water loss—compared with ingestion of the two alternatives.

Among commercial electrolyte-replacement options, the best-known are sports drinks like Gatorade and Powerade, although most contain either high sugar levels or sugar replacements that can cause gas and bloating.

In recent years, ever-increasing choices include chewable tablets and the more common powders and capsules to be mixed with water. For the latter, “best-of” lists include “best overall,” “best organic,” “best for keto and one “best for runners” selection that adds caffeine for an extra boost —though caffeine also shows up in many electrolyte supplements.

“Best budget” on this list and others is Pedialyte, a liquid originally prescribed for rehydration following illness, although one Amazon commenter complains that the unflavored option “tastes so bad I would rather drink from the Gulf of Mexico after the BP oil spill.”

A confusing entry on some lists is Essentia Water, described as “supercharged alkaline water infused with trace amounts of electrolytes,” although the ingredients list notes “Per serving: 0 mg sodium, 0 mg potassium, 0 mg magnesium.”

Among more natural solutions, “coconut water”—usually unadulterated, direct from the inside of coconuts—is popular both for its electrolytes that include sodium, potassium, calcium and magnesium, and for having few calories and little sugar. Cow’s milk is “somewhat of an unsung hero…. with a rich supply of electrolytes,” according to Healthline—as are other dairy products as well as those made from soy.

Fruit juices— notably “watermelon water” but also orange and tart cherry juices—provide good amounts of electrolytes but have the drawback of little to no sodium plus high levels of sugar. Foods high in potassium include fruits like bananas, vegetables like sweet potatoes and spinach; and many nuts.

After several bouts of dehydration following summer exercise—resulting in muscle cramps, dizziness and nausea—I looked for electrolyte options that did not involve commercial drinks or fizzy-flavored mixes from tablets and powders. In hot weather, large quantities of lemonade filled with ice and diluted with water has worked quickly and well.

Year-round, before and after some exercise, I eat lemon-flavored chewable electrolyte tablets called SaltStick Fastchews, which also come in orange, watermelon and peach. To prepare for coronavirus vaccination, besides chewing a few of these, I hope to plan a pre-vaccine day of favorite electrolyte-rich foods: an avocado and an orange; chicken soup; yogurt and milk—and maybe ice cream.


—Mary Carpenter

Mary Carpenter has been closely following Covid-19 developments.



8 thoughts on “Preventing Post-Covid Vaccine Effects

  1. Nancy says:

    I drank gatoraide before, during and after and experienced NO side effects! Highly recommend this approach, lots of electrolytes!

  2. Mallisa says:

    I had a terrible reaction from both first and second dose of the Moderna Vaccine which caused me two lumps on my shoulder and one on my neck. My whole body was in a LOT of pain, but thank God am feeling much better after taking some soup and electrolytes.

  3. Becky Forman says:

    Had a grand mal siezure after getting first shot of Moderna. Went to hospital for 2 days. Had electrolytes among other things. Was asked by nurse if I was on a low-salt diet. Showed up low salt in my blood. Turns out the PEG in Moderna causes low sodium and that is the problem with the vaccine.

  4. Kimberly says:

    Geez- I wish I had read this before my 2nd shot! I was hospitalized 4th day after for severe dehydration/violent 3-day migraine- I thought my brain was going to explode. Could not keep fluids in or down. And here, I kept well hydrated but only on water. I am now sharing the heck out of the advice in the article! Thank you.

  5. Elaine says:

    Thank you for the info as a nurse..I had a mild re-emergence of my covid symptoms after the 1st dose. Mine are strange pains in neck and skull and arthritis. The extra hydration is a great idea I will spread to others!

  6. Jane says:

    This morning, on the way back from getting our first shots of Covid vaccine, my friend and I stopped at Starbucks to pick up a pair of lattes and incidentally a couple boxes of Thin Mint cookies, the first Girl Scouts cookies we’ve seen this season. Now, I’m so pleased to see that some of the cookie’s nutritional ingredients match some of Mary’s recommendations: sodium, calcium, potassium and, of course our fave carb, sugar! Washing down a partial stack of cookies with the warm milk/caffeine mixture has never felt so… RIGHT!

  7. Catharine Keatley says:

    I wish I had read this before my second shot. This is the best and most complete information I have seen.

  8. Carol says:

    Thank you for this! Having 2nd shot on March 6 and have been warned about after effects.
    I can’t stomach Gatorade but will try to do other suggestions

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