Possible side effects related to oral collagen supplements include a persistent unusual aftertaste, and decreased appetite, notes Elavonne Beauty. The collagen in Youtheory supplements is derived from cows and chickens, as shown on Youtheory..
People who are taking medications or who have existing medical conditions should consult a doctor before taking Youtheory collagen supplements, notes the Youtheory website. The daily recommended dose of Youtheory collagen contains 6 grams of collagen. A similar collagen supplement is likely safe when taken orally in doses of fewer than 2 grams daily, notes Web MD. There is insufficient research to determine the long-term effects of taking Youtheory collagen supplements, as of 2015.