In the opinion of Public Citizen, an advocacy group, the FDA erroneously allowed it to be labelled without stating that it is only approved for use by totally blind people. However, FDA updated its press release on Oct. 2, 2014 to clarify the approved use of Hetlioz, which includes both sighted and blind individuals. The update did not change the drug labeling (prescribing information). Toxicity
Experiments with rodents revealed fertility impairments, an increase in certain cancers, and serious adverse events during pregnancy at dosages in excess of what is considered the "human dose". See also
Discovery and development of melatonin receptor agonists

References
External links
"Tasimelteon". Drug Information Portal. U.S. National Library of Medicine.
A small assessment of sustained release of 0.4 mg belladonna alkaloids and ~60 mg phenobarbital (1 grain) was performed in patients with functional GI disorders (i.e., gastric hyperacidity, dyspepsia, pyrosis, gas pains and epigastric distress. Overall, 23 of 25 patients reported complete or significant relief of symptoms. Hock also examined the effect of 0.25 mg belladonna alkaloids and 50 mg phenobarbital sustained release formulation in 82 clinical practice patients with various gastrointestinal disturbances including “functional distress” over 27 months. Of the 82 total patients, 33 patients reported a 50-75% and 20 reported a 75-100% improvement. There were specific reports of improvements in pain and bowel habits in over half of the patients. One of the earliest randomized double-blind clinical trials of belladonna alkaloids + phenobarbital was in 1959 by Lichstein et al. The study involved 75 patients with unstable bowel (whose symptoms are typical or similar to a current diagnosis of IBS) to investigate the combination therapy of an anticholinergic with the addition of phenobarbital against placebo over 15 months. Of these patients, 20 were treated with placebo, 43 were treated with 50 mg phenobarbital in combination with 0.25 mg Belladonna alkaloids, and 12 received both therapies (patients who lacked a response were switched therapy). Of those receiving the belladonna alkaloids / phenobarbital only, 75.6% reported a mean improvement (2+ or better) in all categories. Among the placebo patients only, only 29.8% reported mean improvement in symptoms.