From the Guidelines

Ramelteon, also known as Rozerem, is a melatonin receptor agonist that is used to treat sleep onset insomnia in adults.

The evidence for the effectiveness of ramelteon is weak, with marginal reduction in sleep latency and no significant improvement in sleep efficiency or sleep quality 1.
Ramelteon is suggested for use in adults with sleep onset insomnia, based on trials of 8 mg doses 1.
The medication has a low potential for adverse events, with no significant difference from placebo in terms of adverse effects 1.
Commonly reported adverse events include headache, nausea, upper respiratory infection, and nasopharyngitis 1.
There is no consistent evidence of next-day impairment associated with the use of ramelteon 1.

The recommended dose of ramelteon is 8 mg, taken orally before bedtime 1.
The medication should be used with caution in older adults, as it may cause residual effects such as dizziness and somnolence 1.

Ramelteon may be considered for use in adults with sleep onset insomnia who have not responded to other treatments 1.
The medication should be used in conjunction with good sleep hygiene practices, such as maintaining a consistent sleep schedule and creating a relaxing sleep environment 1.

From the FDA Drug Label

Ramelteon is a melatonin receptor agonist with both high affinity for melatonin MT1 and MT2 receptors and relative selectivity over the MT3 receptor

Ramelteon is a melatonin receptor agonist that acts on MT1 and MT2 receptors, which are involved in the maintenance of the circadian rhythm underlying the normal sleep-wake cycle 2
It has no appreciable affinity for other receptors, such as GABA, serotonin, dopamine, noradrenaline, acetylcholine, and opiates
The major metabolite of ramelteon, M-II, is pharmacologically active and has a higher systemic exposure than the parent molecule
Ramelteon is used for its sleep-promoting properties.

Ramelteon, also known as Rozerem, is a melatonin receptor agonist approved for the treatment of insomnia characterized by difficulty falling asleep 3, 4, 5, 6, 7.
It is a highly selective agonist for melatonin subtypes 1 and 2 receptors, which are believed to mediate the circadian rhythm in mammals 4, 5, 6.

Ramelteon acts specifically on MT(1) and MT(2) melatonin receptors, with negligible affinity for other receptors in the brain, including opiate, dopamine, benzodiazepine, and serotonin receptors 4, 5, 6.
Its primary action in sleep promotion is not a generalized gamma-aminobutyric (GABA)-ergic central nervous system depression, but rather it acts as a melatonergic agonist in the suprachiasmatic nucleus (and at other central nervous system sites) 6.

Ramelteon has been shown to be effective in reducing sleep latency and increasing total sleep time in patients with chronic insomnia 3, 4, 5, 6, 7.
It has also been shown to improve sleep efficiency and reduce the number of nighttime awakenings in some studies 3, 4, 6.

Ramelteon is generally well tolerated, with the most common adverse events being somnolence, dizziness, fatigue, and nausea 3, 4, 5, 6, 7.
It is not associated with next morning hangover effects, reductions in alertness, or withdrawal symptoms 4, 6, 7.
Ramelteon has been shown to have no potential for abuse or dependence 5, 6, 7.