How many Emergen-C per day is OK to drink?

If you purchase a product through a link on this page you will get a 5% discount on, and we may earn a commission. Learn more.

Have you heard of a “quarantini”? This is a mixed drink where you add vodka to – you guessed it – Emergen-C! Of course you need to serve it up in a martini glass… Well, it’s not necessarily something we endorse (neither do the makers of Emergen-C), but we do marvel at the creativity and resourcefulness that we’ve seen during these crazy times. It’s important to remember that dietary supplements are different from other foods and beverages because they aren’t meant to be consumed as much as you like. The daily dose is important! This then leads many people to ask – how many Emergen-C per day is OK to drink? We won’t keep you waiting, we say don’t take more than 2 servings per day. To find out why, read on.

Just to clarify, we are not affiliated in any way with the company that makes Emergen-C. However, let’s have a look at what this product contains, the potential side effects, and fig how many is really OK.

Here’s what we’ll cover:

Emergen-C: The immune system booster

It’s important to know that there are a few different products from Emergen-C. The most well-known version of this product is an orange-flavored powdered beverage that you mix into water or shake into a bottle, and there is also an “Immune+” variant with added vitamin D and a proprietary complex. They also make other products like gummies and chewables that have mostly the same nutrition profile as the powdered beverage. For this discussion we’ll focus on the main product:

Click image for details

It also comes in other fun flavors like acai berry and tropical!

The main ingredient is vitamin C, but it also has B vitamins, zinc, magnesium, and other nutrients important for immune health. For this discussion we’ll focus on the original product because it tends to have the highest levels of the nutrients. As we’ve discussed before, gummies are often lacking in the nutrition department.

Emergen-C is a great option for people to boost their immunity during cold and flu season. However, many people also say that the product helps give them energy during the day. This is not surprising, because vitamin C and some of the B vitamins have been linked to decreased levels of fatigue. Because it’s got a bunch of different vitamins and minerals in addition to vitamin C, it also makes a fairly decent multivitamin for the average person.

What are the key ingredients in Emergen C and what do they do for your immune system?

Vitamin C is the number one ingredient in all the different versions of Emergen-C. You can think of it as the “hero” ingredient. The powdered products and chewables all have 1000 mg of vitamin C, while the gummies tend to have lesser amounts because there is only so much vitamin C that can be mixed into a gummy without making it taste… gross. Vitamin C is by far the most well-known ingredient for immunity, going back many decades to the advocacy of the renowned chemist, Linus Pauling. For more background, you can check out these pages on the Linus Pauling Institute and the NIH Office of Dietary Supplements fact sheet.

Some people think that the effect of vitamin C on immunity has been debunked, but a number of clinical trials have proven that it works to help shorten respiratory tract infections. This is especially true in people under physical stress, like soldiers and marathon runners. The caveat is that you do need to take a significant amount every day to get the job done, at least 200 mg, and many studies have shown benefits with 500-1000 mg per day.

Emergen-C also has other ingredients that are important for the immune system. B vitamins like thiamin, riboflavin, niacin, B6, B12, and folate are all essential for immune cell production. It also has zinc, an essential mineral that plays a role in a huge number of physiological processes. Zinc is well known to support immune system health.

So – how many Emergen-C per day is OK to drink?

OK, so to answer this question, we need to take a look at the nutrients contained in Emergen-C, and how those levels relate to the daily recommendations and the daily “tolerable upper limits” for adults. We’ve already had a look at this question from the angle of pregnancy. The Food and Nutrition Board of the National Academy of Sciences (formerly called the Institute of Medicine) has developed these values in a series of “Dietary Reference Intakes.” Let’s take a look at how taking Emergen-C once or twice per day would compare to these recommendations in the table below:

Nutrient1 Serving of Emergen-C2 Servings of Emergen-CDaily Recommendation for AdultsUpper Limit for Adults
Vitamin C1000 mg2000 mg85 mg2000 mg
Thiamin.36 mg.72 mg1.4 mgND
Riboflavin.39 mg.78 mg1.4 mgND
Niacin4 mg8 mg18 mg35 mg
Vitamin B610 mg20 mg1.9 mg100 mg
Folate167 mcg DFE333 mcg DFE600 mcg DFE1000 mcg
(as folic acid)
Vitamin B1225 mcg50 mcg2.6 mgND
Pantothenic Acid2.5 mg5 mg6 mgND
Calcium50 mg100 mg1000 mg2500 mg
Phosphorous38 mg76 mg700 mg3500 mg
Magnesium53 mg106 mg350 mg350 mg
Zinc2 mg4 mg11 mg40 mg
Manganese.5 mg1 mg2 mg11 mg
Chromium10 mcg20 mcg30 mgND
Sodium65 mg130 mg1500 mgND
Potassium200 mg400 mg2900 mgND
DFE: dietary folate equivalents, ND: not determined. Source: Food and Nutrition Board of the National Academies. Dietary Reference Intakes for adults. RDAs and AIs for vitamins and minerals, tolerable upper limits for vitamins and minerals.

The first thing to note is that NONE of the nutrients are above the tolerable upper limit if you are consuming a single serving per day. However, if you take it twice per day, you will hit the upper limit for vitamin C. Hold that though – we’ll get back to it…

The higher levels of B vitamins are not an issue. These are most likely included because B vitamins play an essential role in the immune system. B vitamins are important to support cell division, and this is a critical factor for your immune cells to reproduce and attack germs. But in addition, they support healthy energy metabolism in the cell and help convert food to energy. Because of this role in cellular energy production, they can be helpful if you are down on energy, for example when you’re sick. Vitamin B12 has no established upper limit, as there are no known adverse effects associated with vitamin B12 intake. This doesn’t mean you should just take as much as you want, but the levels included in Emergen-C are fairly typical.

Most of the nutrients are not only well below any of the upper intake levels, but they are also somewhat below the recommended intake levels. However, this is OK because you are eating other foods anyway, so there’s no need to get everything from a supplement. OK, so back to vitamin C – why is the level so high?

The vitamin C level in Emergen-C is way above the typical intake recommendation because studies show taking 500-1000 mg of vitamin C can have a positive impact on preventing or controlling upper respiratory tract infections. From a safety standpoint, this is not an issue. In fact, most mammals, except for some primates, actually make their own vitamin C in the liver. And levels of vitamin C go up substantially when they are under stress or fighting an infection

However, because of the high levels of vitamin C, this also means that you are going to bang up against the upper limit with only 2 servings per day. So what is this upper limit based on? Well if you read the full DRI report (which we don’t recommend unless you suffer from insomnia), mentions diarrhea as a complication of taking too much vitamin C. Well, that doesn’t sound pleasant.

Actually, it turns out that vitamin C is used in one of the popular coloscopy prep solutions to help “clear things out” before the procedure. Other than that, vitamin C is actually really safe. There are many studies where much larger amounts of vitamin C have been injected with no adverse reactions. However, if you want to avoid a case of the squirts, probably best to keep below 2 servings of Emergen-C per day

Bottom line

To boil it all down, it is safe to take Emergen-C once or twice per day at most. Any more than that you run the risk of having a bad “gastrointestinal experience” because of all the vitamin C. Just like any supplement, it’s not meant to be taken whenever you want like a typical food or beverage. That’s really the main difference between a food and a supplement in the first place. So, is it OK to have a “quarantini” from time to time? Sure, why not! But don’t tempt fate – more than 2 Emergen-Cs and you may have some unexpected hangover symptoms.

Stay well!