This study concluded that a small dose of 4g (about ¼ of a tablespoon) per day was unlikely to cause adverse effects, but 286g (over 19 tablespoons) could lead to excess iodine intake.Darias-Rosales, J., Rubio, C., Gutiérrez, Á. J., Paz, S., & Hardisson, A. (2020). Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmata and Chondrus crispus). Environmental Science and Pollution Research International, 27(36), 45737–45741. While it’s tough to translate this data into the ideal sea moss dosage, 4g (4,000mg) of pure Irish sea moss gives you about 16μg (micrograms) of iodine. The recommended daily amount of iodine for adults is 150μg, and the upper limit is 1,100μg per day. This means that most commercial sea moss supplements are likely safe for daily use (especially considering they all use a lot less sea moss than the study).National Institutes of Health. (2022). Iodine - Fact Sheet for Consumers. NIH.