You two will not be able to sleep. Is there a way you can stay up later?
-induced insomnia is the worst. Since the current preference for amphetamines on the market today is to make them as long-lasting as possible one can easily end up in a situation where they cannot sleep, need to be up for the new day, and are confronted with the choice of trying to induce sleep artificially or just pull through and re-dose to make up for the lack of sleep.
Vyvanse is extremely long lasting. Its half life is about 9 and a half hours give or take an hour or two. That means that in most people, the medication has some effect for up to 14 hours. Also, after taken it takes about 20 minutes to kick in.
At 8 hours in, the levels of Vyvanse are about 60% of their peak. At 10 hours in, the levels are about 40% of their peak. At 13 hours in, they are at about 20% of their peak.
As for melatonin, most people think it is a natural sleeping pill. Melatonin on its own won't induce sleep, and is usually only effective in short-term applications. It's more correct to think of melatonin as a 'darkness' signaler because it tells the brain that it needs to prepare for a night time. If taken in the evening or when it's dark, melatonin can speed up sleep preparation, and it can tell the body clock to shift its sleep cycle to an earlier time.
Tablet sizes average 3-5 mg. Adult males only need 150 micrograms, and the average female needs only 100 micrograms (a microgram is 1/100 th of a milligram). Melatonin's half life is very short, and is only active in your system for about 20 minutes.
If you take more than an hour to fall asleep, or you need to shift your sleep more than an hour, consider taking time-released melatonin. It is also important to use a high-quality, standardized melatonin supplement. Try to find the lowest dose available and do not cut the pill . Since melatonin tablets are coated to provide slow release, cutting them will ruin their long-term potency.
When to take: Depending on the severity of the sleep problem, take time-released melatonin 1 to 3 hours prior to the time you usually fall asleep. Since time release melatonin only lasts for 3 - 4 hours, any need to shift sleep schedules more than 3 hours may require taking another pill in 3 or 4 hours.
Induce sleep (less than 1hr)
If it takes an hour or less to fall asleep, then standard melatonin in the lowest mg size is a good option.
When to take: One to two hours before desired sleep.
For frequent or awakenings that last more than one hour, consider taking 1 sublingual and a time-released melatonin tablet. Take the time release tablet first and then place the sublingual tablet under your tongue.
If you need to get up in the morning within 2-3 hours, Take regular instead of time release melatonin. Time release melatonin may last into the waking hours, causing confusion and mood problems.
So it should be clear that melatonin won't do the trick because its not like a sleeping pill. To sleep you'd have to sedate yourself badly and then sleep way longer into the day and feel horrible. Trust me, take it when you get up and don't waste it.