Can You Take Whey Protein Before Going to Bed?

The amount of time that passes between one night’s dinner and the next morning’s breakfast can span 12 hours, or even more. If you're serious about protein intake -- for example, as a bodybuilder or serious athelete -- your body might need a steady flow of nutrients and amino acids during this time. Consuming a protein shake before bedtime is an effective strategy, but whey protein might not be the best choice. Before trying any type of protein supplement, consult your doctor.


Whey and Blood Amino Acid Levels

A spike in blood amino acid levels occurs any time you consume protein, which breaks down into individual amino acids that are then absorbed into your small intestine. These amino acids circulate through your bloodstream and help support muscle growth and maintenance. As a fast-absorbing protein, whey quickly spikes your blood amino acid levels -- It causes them to increase by 300 percent after just one hour, according to bodybuilder John Berardi. However, they also fall within a few hours, and won't cause a sustained enough increase in your blood amino acid levels to last though the night.

Reach for Casein

Berardi suggests choosing casein protein over whey when it comes to a pre-bedtime protein shake. Casein protein doesn’t deliver the short-lived spike in blood amino acid levels like whey. Instead, it delivers a smaller increase in blood amino acid levels over a longer period of time. Berardi says casein increases blood amino acid levels by up to 35 percent over a period of seven or more hours. Casein might not be as effective as a post-workout shake compared with whey, but it is superior as a nighttime source of protein.

Use Whey Post-Workout

Because of its fast-absorbing proteins, whey makes for an ideal post-workout shake. It rapidly provides your muscles with the amino acids they need to synthesize new protein after your gruelling workout. If you work out in the evening, feel free to consume whey at night -- but don't rely on it as an overnight workout supplement, consider it a post-workout snack.


Mixing whey with milk can extend its effect on your blood amino acid levels. The protein in milk is naturally about 80 percent casein, so a whey/milk mixture might help increase your blood amino acid levels over a longer period of time. You will still get the initial burst of amino acids about an hour after consuming the supplement, but the milk will help slow down digestion and absorption of the whey for a prolonged effect. The mixture might not be as effective as casein overnight, but the milk will increase the overnight benefit of whey.


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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or