Ray Peat on Gelatin and Glycine

Short answer: Ray Peat argued that modern diets have too much muscle meat and too little gelatin. Gelatin has no tryptophan and very little cysteine, so it balances the amino acids of meat, calms inflammation, helps blood sugar and improves sleep.

What Ray Peat wrote about gelatin

His core argument: eating only muscle meat puts the same amino acid mix into the blood as extreme stress does, when cortisol breaks down your own muscle. Source: Gelatin, stress, longevity

Gelatin contains no tryptophan and only small amounts of cysteine, methionine and histidine. About 35% of it is glycine, with proline and alanine next. Source: Gelatin, stress, longevity

Tryptophan and cysteine in excess suppress the thyroid, and tryptophan feeds serotonin, which raises cortisol. Restricting only tryptophan or cysteine extends lifespan in animals more than restricting calories. Source: Gelatin, stress, longevity

He wrote that gelatin and glycine help insulin lower blood sugar, and that gelatin had been used to treat diabetes for over a hundred years. Glycine also restrains the release of fat from storage. Source: Gelatin, stress, longevity

He reports his own experience: the first time he took several grams of gelatin before bed he slept nine hours without waking. Friends told him of long-standing pain easing within days on 10 to 15 grams a day. Source: Gelatin, stress, longevity

He rejected the cartilage-building explanation for joints. Gelatin's benefit in arthritis is anti-inflammatory, he argued, not a matter of supplying raw material. Source: Gelatin, stress, longevity

Gelatin lacks the amino acids that feed polyamine growth signals and is soothing to the intestine, so he wrote that it should be a regular part of the diet. Source: Meat physiology, stress, and degenerative physiology

What he suggested in practice

• 5 to 10 grams with a large serving of meat, so the amino acids arrive in balance.
• Gelatinous broth or gelatin at bedtime, to stop the stress of the night.
• He wrote that even 100 grams a day would not seem unreasonable, and that some people find amounts in that range reduce fatigue.
• Broth from beef or lamb for both gelatin and minerals.

Where he wrote about it

This topic comes up in 38 of the articles on his site. These are the most relevant ones:

• Gelatin, stress, longevity · original on raypeat.com ↗
• Tryptophan, serotonin, and aging · original on raypeat.com ↗
• The Cancer Matrix · original on raypeat.com ↗
• Osteoporosis, aging, tissue renewal, and product science · original on raypeat.com ↗
• Growth hormone: Hormone of Stress, Aging, and Death? · original on raypeat.com ↗
• Regeneration and degeneration: Types of inflammation change with aging · original on raypeat.com ↗
• Multiple sclerosis, protein, fats, and progesterone · original on raypeat.com ↗
• Bleeding, clotting, cancer · original on raypeat.com ↗

My take

The first peptide you should take is beef gelatin. I drink 20 g in warm milk with sugar when I wake up and again an hour before bed. Glycine and proline are also what gut mucus is built from.

Quick answers

How much gelatin did Ray Peat recommend?

He suggests 5 to 10 grams with a large serving of meat, describes taking several grams at bedtime, and writes that up to 100 grams a day would not seem unreasonable.

Why did Ray Peat recommend gelatin?

Because it has no tryptophan and little cysteine, it balances the amino acids of muscle meat, lowers the stress response, helps blood sugar and improves sleep.

Did Ray Peat prefer gelatin or collagen?

His article is about gelatin, which he describes as the cooked form of collagen. They have the same amino acids.