The current adverse event reporting system for dietary supplements lacks the ability to collect and analyze ongoing case reports in sufficient numbers to detect health issues. We conducted an online survey to collect data on skin manifestations due to supplement use in consumers and to identify the suspected products and ingredients. An online survey was conducted among 63,737 dietary supplement users in 2016. Those who self-reported experiences of skin anthema or itching caused by supplement use and recognized a causal relationship as almost certain (0.8%) were invited to provide further details of symptoms and products. Most of the users experienced mild symptoms with “itching and/or rash of body part.” After the onset of skin manifestations, 69.3% ceased supplement use, while 26.6% continued supplement use, including those who reduced the amount or frequency of use. Respondents who visited the hospital in response to symptoms accounted for 26.0%, while 53.3% did not seek treatment. The products used were identified in 155 of 300 eligible respondents. Although those products were composed of multiple ingredients, the accumulated data suggested that cutaneous symptoms were related to the following constituents: “Peptides or animal by-products” (31.0%), “Herbal/Botanical” (23.2%) and “Fats and lipid” (13.5%). Conducting an online survey to elicit information directly from consumers identified components of supplements that are involved in skin manifestations that could lead to serious damage, and may fill a void in the current adverse event reporting system.