While taking amino acids before bed may help to promote muscle repair and growth, it is important to keep in mind that amino acids are proteins, and as such, may cause digestive issues if taken too late in the evening. It is best to consult with a doctor or nutritionist to determine the best time to take amino acids and any potential side effects. Additionally, taking amino acids before bed may interfere with sleep, so it is important to take them at least 2-3 hours before bedtime.