Slisli Y et al showed that salmon calcitonin is an extremely potent suppressor of slow wave sleep, producing an almost 30-h long insomnia.[4] Carman JS et al showed that when synthetic salmon calcitonin given in the evening, it appeared to delay sleep onset.[27] On the contrary, Nakajima Te al showed that intramuscular calcitonin improved depth and maintenance of sleep in a case report.[28] Serum calcitonin level correlated with bad sleep, and may have influence on sleep quality. This evidence concerns the gene CALCA and insomnia measurement.