A study performed before a clinical trial on type I and III injectable human collagen only claims side effects of slight redness and discomfort at or near the injection site, states the National Center for Biotechnology Information. The study concludes that researchers observed no serious side effects from these two types of collagen. One patient in another study, performed in 2000, experienced an allergic reaction to a specific collagen-based injectable product, called Dermalogen.
Common risks of using collagen-based soft-tissue fillers include bruising, itching or rashes, according to the U.S. Food and Drug Administration. Infections or necrosis are possible, but less common, side effects. Anaphylaxis, blindness or other vision abnormalities, stroke, or damage to the skin or lips are rare adverse effects. The FDA approves soft-tissue filler therapies based on clinical studies and, as of 2015, warrants them generally safe, but there are no clinical studies available for using soft-tissue fillers together with other therapies, such as Botox, explains the FDA.
Collagen is a tough protein created by the human body; although there are at least 16 types, most collagen can be classified as type I, II or III, reports Medical News Today. Type I collagen is as strong as steel. However, collagen production decreases with age, leading to wrinkles. Collagen is preferred for a variety of medical uses since the body reabsorbs it easily, and it is an all-natural ingredient. The collagen used in medical therapies may be from human, cow or pig sources.