Essential Amino Acids for Women: A Plain Guide

I spent years taking more than 15 supplements, at different times, for different things, never knowing what was working. My supplement cabinet looked like I was studying for a PhD in wellness.

When I finally stripped it all back, what was left were the raw materials. Amino acids were at the top of that list.

Essential amino acids are the nine building blocks of protein that your body can't make on its own, so they have to come from food or a supplement. Of the nine, leucine is the one most closely tied to building muscle protein, and research suggests the proportion of leucine in the mix matters more as you get older.

What essential amino acids are

Every protein in your body is built from the same twenty amino acids. That includes your muscle, your skin, your hair, and the enzymes doing their jobs quietly in the background. Your body can make eleven of those twenty. The other nine it can't, which is why they're called essential: leucine, isoleucine, valine, lysine, methionine, phenylalanine, threonine, tryptophan and histidine.

Your body is breaking proteins down and building new ones all day long. To keep building, it needs a steady supply of all nine.

Why leucine gets the attention

Muscle protein synthesis is the ongoing process of building new muscle protein. Leucine is the essential amino acid most closely tied to switching that process on.

In a 2006 study, researchers gave younger and older adults a drink of essential amino acids. One version had leucine at about the level found in whey protein (26%). The other was enriched to 41% leucine. The younger group responded to both. In the older group, only the leucine-enriched version produced the full response. The researchers concluded that a higher proportion of leucine could make up for the weaker response they saw with age.

Research done in women

A lot of muscle research has been done in men. A 2015 study from the University of Nottingham looked specifically at older women, with an average age of 66. One group of eight women drank 3 grams of a leucine-enriched essential amino acid blend (40% leucine). Another group of eight drank 20 grams of whey protein. The 3 grams produced a muscle-building response similar to the 20 grams of whey, both at rest and after exercise.

It's a small study, done under lab conditions, and it measured a response over a few hours, not results over months. It's still one of the clearer looks at how women's muscle responds to a small, leucine-rich dose.

Food comes first

You get essential amino acids every time you eat a complete protein: eggs, fish, chicken, beef, dairy, soy. Researchers have pointed out that leucine-rich protein foods can do this work too.

I cooked at home. I cared about protein. I still do.

But plenty of days don't go the way I planned. I'll eat a great dinner Tuesday, then realize at 3pm Thursday that coffee and a handful of something from the kids' snack drawer probably wasn't lunch. So I don't save it for the bad days. I take it every morning, and when a day falls apart, I already know the foundation's there.

What's in KESSARA

KESSARA is built on a blend of all nine essential amino acids, with a 40% leucine ratio. Each serving has 4 grams, along with magnesium bisglycinate and electrolytes.

That research was done on a leucine-enriched blend, not on KESSARA, and no study is a promise about how one glass feels on an ordinary Wednesday. What I can tell you is why I started there.

Nobody admires a foundation. You notice it when it's missing.

If you want to be here from the beginning, join the Founding Circle.

Sources

• Katsanos CS, Kobayashi H, Sheffield-Moore M, Aarsland A, Wolfe RR. A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. American Journal of Physiology-Endocrinology and Metabolism. 2006;291(2):E381-7. https://pubmed.ncbi.nlm.nih.gov/16507602/
• Bukhari SS, Phillips BE, Wilkinson DJ, et al. Intake of low-dose leucine-rich essential amino acids stimulates muscle anabolism equivalently to bolus whey protein in older women at rest and after exercise. American Journal of Physiology-Endocrinology and Metabolism. 2015;308(12):E1056-65. https://pubmed.ncbi.nlm.nih.gov/25827594/
• Is leucine content in dietary protein the key to muscle preservation in older women? (commentary). https://pmc.ncbi.nlm.nih.gov/articles/PMC6248570