High Fructose Corn Syrup: What It Is, HFCS vs Sugar and What Studies Show

High fructose corn syrup (HFCS) is a liquid sweetener made from corn starch. Manufacturers first turn the starch into corn syrup, which is almost all glucose, then use enzymes to convert part of that glucose into fructose. The two common grades are HFCS-42 and HFCS-55, named for their fructose percentage. Table sugar (sucrose) is also made of glucose and fructose, which is why the FDA says it is not aware of evidence that foods with HFCS differ in safety from foods with similar amounts of other caloric sweeteners. The more useful question is how much added sugar a food contains, whatever its source. Below: what high fructose corn syrup is, how it compares with sugar, how to spot it on a label, and what controlled studies actually found.

Peptide Labs does not sell high fructose corn syrup or any sweetener as a product. This article is general information about a common food ingredient, not medical advice.

What is high fructose corn syrup?

According to the FDA, high fructose corn syrup is produced by adding enzymes to corn syrup so that some of its glucose is converted into fructose. It is called “high” fructose only in comparison with regular corn syrup, which is essentially pure glucose. The FDA regulates it under 21 CFR 184.1866, the rule that lists it as a food substance generally recognized as safe for its intended uses.

Two grades dominate the US food supply. HFCS-42 contains 42 percent fructose and is used in processed foods, breakfast cereals, baked goods and some beverages. HFCS-55 contains 55 percent fructose and is used primarily in soft drinks. In both, the rest is mostly glucose plus water. Food makers like HFCS because it is a stable liquid that blends easily into drinks and batters, keeps baked goods moist, and helps with browning.

High fructose corn syrup vs sugar: the real differences

Table sugar is sucrose, a molecule in which one glucose and one fructose are joined by a chemical bond, so it is split evenly between the two. The FDA points out that the glucose-to-fructose ratio of HFCS is similar, and that the main structural difference is the bond: in sucrose a bond joins glucose and fructose, while in HFCS the two sugars float freely. Enzymes in the small intestine break that bond quickly, so by the time the sugars are absorbed, the body sees glucose and fructose either way.

Calorie for calorie, these are all caloric sweeteners. The FDA’s practical advice is the same for HFCS and sucrose: limit added sugars of every kind. If you are comparing honey and table sugar for other reasons, the same added-sugar rule applies to honey too.

Is high fructose corn syrup bad for you? What research shows

HFCS became controversial in the 2000s. A widely cited 2004 paper by Bray, Nielsen and Popkin in the American Journal of Clinical Nutrition proposed that HFCS in beverages may have played a role in rising obesity rates, partly because HFCS use climbed during the same decades. That paper presented a hypothesis based on trends, not a trial showing cause and effect, and it prompted many studies comparing HFCS directly with sugar.

Those direct comparisons matter most. A 2022 systematic review and meta-analysis by Li and colleagues in Frontiers in Nutrition pooled four randomized controlled trials with 767 participants in which HFCS and sucrose were given at matched calories, on average about a fifth of daily calories. The authors found no meaningful differences between the two sweeteners in body weight, waist size, BMI, fat mass, blood pressure, fasting glucose or blood lipids. C-reactive protein, a marker of inflammation, was higher with HFCS. The analysis included only a handful of trials, some short, and two authors worked for a biotechnology company, so the CRP finding needs confirmation.

The broader research on fructose-containing sugars points in one direction: large amounts of added sugar, especially in sugary drinks, are linked with less healthy diets, and that applies to sucrose as much as HFCS. Swapping one for the other at the same amount is unlikely to change much. Cutting back on sweetened drinks and sweets changes the total. For practical ideas, see our guides to refined carbs, low glycemic foods and how to stop sugar cravings.

Myths and facts

• Myth: HFCS is mostly fructose. Fact: the common grades are 42 or 55 percent fructose, close to sugar’s 50 percent.
• Myth: HFCS is chemically unique and dangerous in small amounts. Fact: FDA reports no known safety difference from similar amounts of sucrose or honey.
• Myth: products made with cane sugar are a health upgrade. Fact: cane sugar still counts as added sugar on the label.
• Fact: FDA says HFCS-55, the higher-fructose grade, is used mainly in soft drinks.

How to find HFCS on a food label

HFCS must appear by name in the ingredient list as “high fructose corn syrup.” In 2010 the Corn Refiners Association petitioned the FDA to allow the name “corn sugar” instead. The FDA denied the petition on May 31, 2012, explaining that the word “sugar” would not accurately describe a syrup, that “corn sugar” has long meant dextrose, and that the term has traditionally described sweeteners suitable for people with hereditary fructose intolerance or fructose malabsorption.

On the Nutrition Facts panel, HFCS is counted in Total Sugars and in the Added Sugars line. The FDA label rules set a Daily Value of 50 grams of added sugars per day, based on a 2,000 calorie diet, and the Dietary Guidelines advise keeping added sugars below 10 percent of calories. The percent Daily Value on the label is the quickest way to compare two products: 5 percent or less is low and 20 percent or more is high, per FDA’s label guidance. Sugars that occur naturally in milk, whole fruit and vegetables are not counted as added sugars, which is why the sugar in whole fruit sits in a different category.

Who may want to pay closer attention

• People diagnosed with hereditary fructose intolerance, a rare inherited condition, follow strict fructose avoidance under clinician guidance; HFCS, sugar and honey all contain fructose.
• People who notice gut symptoms with fructose: foods with more fructose than glucose are a focus of the low FODMAP approach, ideally worked through with a dietitian.
• People managing blood glucose: HFCS affects blood sugar like other caloric sweeteners; ask your clinician or dietitian how added sugars fit your plan.
• Anyone choosing a sugar-free option instead: no-calorie sweeteners such as sucralose and saccharin raise their own questions.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a digestive or metabolic condition. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Sucralose and Saccharin: FDA Status, Studies and Side Effects, How to Stop Sugar Cravings: Why They Happen and What Research Supports, Refined Carbs vs Whole Grains: Simple and Complex Carbs Explained.