Though it is a derivative of melatonin, they have their differences. Below is a comparison of them.
1.Different categories. (Tasimelteon is regarded as an api, melatonin is treated as a nutritional supplement)
Tasimelteon is an active pharmaceutical ingredient and it was granted as an orphan drug by the FDA in 2010, while Melatonin is regarded as a nutritional supplement. China State FDA has different requirements for pharmaceutical ingredients and food supplements.
2. Melatonin is safer.
Researches have shown that low-dose melatonin is safe for children. You can check melatonin powder for more details.
3. Cost Difference. (its pure powder costs 2500 times than melatonin)
1G tasimelteon is worth almost 10kg Melatonin. The cost difference is mainly caused by: 1) the production scale. 2) Synthesis steps.
Small demands as an active ingredient of medicines compared with melatonin with huge demands from the market as a healthcare supplement, melaonin wins easily. The commercialized production scale has reduced melatonin price to about 180usd/kg or less.
4. Synthesis process.
Its shortest synthesis route has 6 steps, and the longest route of synthesis has 18 steps. Longer synthesis steps means less yeild with the same amount of starting materials.
While there is one-step synthesis method for melatonin and even the longest route only has 3 steps. You can check the routes below: