Welcome back to the Barbell Medicine Podcast. I'm Dr. Jordan Fagenbaum. Today on episode 251,

we're going to talk about creatine, including how it works, its effects, safety data,

and a special focus on if it causes hair loss. Basically, this episode of the Barbell Medicine

Podcast has everything you've ever wanted to know about creatine, and then some.

First off, what is creatine? Creatine is a naturally occurring amino acid that is produced

by various tissues in the body, such as the kidney, liver, and the pancreas. It's also found in red

meat, poultry, and seafood, though at relatively low levels. For example, 5 grams per day is the

often recommended supplemental dose, whereas red meat and fish contain about 4 grams of creatine

per kilogram, so you need like a full kilo of meat per day, and that's probably not the best way

to get creatine. What does creatine do? Creatine is stored primarily in the skeletal muscle

tissue, about 95% of it is stored there, with smaller amounts in the brain and gonads. It plays an

important role in rapid energy production as part of the phosphocreatine system. During exhaustive

resistance and endurance training, phosphocreatine stores are significantly reduced, so if you're

to increase those, by supplementing creatine, it should improve performance. As far as how it works,

during and after a low load, high repetition resistance training effort that has taken to failure,

ATP levels within the muscle falls somewhere between 30 to 40%. ATP is like the cellular currency

of energy. Anything that you need the cell to do that requires energy, you're going to use ATP.

Now, as these ATP levels are falling, so do stored levels of creatine phosphate in the muscle. While we

make about 1 to 2 grams per day of creatine in the kidney and liver predominantly, supplementing

with creatine at 3 to 5 grams per day increases muscle creatine levels significantly. Thus, by increasing

muscle levels of creatine, it is thought that an individual supplementing with creatine has

greater stores of energy for rapid energy production, although there are other mechanisms that

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