Collagen supplements and collagen peptides are all the rage in the health and beauty world, and they have research-backed benefits. Before you jump on the bandwagon, though, there are some side effects you should keep in mind.
Collagen is a protein — the most plentiful protein in your body, according to the Cleveland Clinic, although production decreases as you age. It's in your muscles, bones, tendons, ligaments, organs, blood vessels, skin, intestinal lining and other connective tissues.
Collagen aids in healing and repairing damaged bones and cartilage. Collagen also helps to maintain the resistance, elasticity and mobility of joints and connective tissue. You can take dietary supplements to improve your collagen levels, but these come with a few possible side effects.
Supplemental Collagen Benefits
Collagen pills may be best known for their effect on skin. Collagen can help increase skin hydration and improve skin elasticity, which may help skin look younger.
Research backs this up, including a study published August 2019 in Nutrients in which 72 women older than 35 showed significant improvements in skin elasticity, roughness and density with an oral collagen supplement during the 12-week trial.
In addition to this small study, a review published January 2019 in the Journal of Drugs and Dermatology found that oral collagen supplements increase skin elasticity, hydration and dermal collagen density.
Collagen Supplement Side Effects
1. High Calcium Levels
According to the U.S National Library of Medicine, high calcium levels or hypercalcemia may occur as a possible side effect of collagen supplements. Specifically, collagen supplements that come from marine sources, like shark cartilage or shellfish, can contain high levels of calcium.
According to the Mayo Clinic, too much calcium in the body can cause:
- Bone pain
- Abnormal heart rhythms
Taking calcium supplements together with this type of collagen should be done with caution and only under the supervision of a physician or dietitian.
2. Allergic Reaction
It's possible to be sensitive or allergic to certain collagen supplements, which can cause a reaction. This is most common with supplements made from shellfish or other marine sources.
Indeed, a case study published October 2016 in Allergology International found that fish collagen caused an allergic reaction in a 30-year old woman with a known marine allergy even when the supplement was produced using high-heat methods.
Signs of an allergic reaction, according to the Mayo Clinic, may include:
- Tingling or itching in the mouth
- Hives, itching or eczema
- Swelling of the lips, face, tongue and throat or other parts of the body
- Wheezing, nasal congestion or trouble breathing
- Abdominal pain, diarrhea, nausea or vomiting
- Dizziness, lightheadedness or fainting
If you have a known allergy to shellfish or other marine allergies, it's important to avoid these supplements, as an allergic reaction could be life-threatening.
3. Bad Taste in the Mouth
Some oral collagen supplements can leave a bad taste in the mouth, according to the U.S. National Library of Medicine. Collagen supplements made from marine or bovine sources usually have a taste and odor that is not very pleasant to most people.
Choosing a high-quality collagen supplement and mixing it into a flavored beverage can help reduce the unfavorable taste.
- U.S. National Library of Medicine: Shark Cartilage
- Biomedical Journal of Scientific & Technical Research: "Beneficial Effects of Collagen Hydrolysate: A Review of Recent Developments"
- Cleveland Clinic: "The Best Way You Can Get More Collagen"
- Nutrients: "A Collagen Supplement Improves Skin Hydration, Elasticity, Roughness, and Density: Results of a Randomized, Placebo-Controlled, Blind Study"
- Mayo Clinic: "Hypercalcemia"
- Allergology International: "Allergy to fish collagen: Thermostability of collagen and IgE reactivity of patients' sera with extracts of 11 species of bony and cartilaginous fish"
- Mayo Clinic: "Food Allergy Symptoms and Causes"
- Journal of Drugs and Dermatology: "Oral Collagen Supplementation: A Systematic Review of Dermatological Applications"