Should I take glycine?

Our read is that increasing glycine intake through sources like bone broth, collagen, gelatin, or glycine powder is reasonable, as supported by Peter Attia and Paul Saladino.

Paul Saladino suggests that inadequate glycine intake can lead to accelerated aging, reduced skin elasticity, increased wrinkles, and various other health issues, while a diet with increased glycine levels can increase healthy lifespan in mice.

Rhonda Patrick, Paul Saladino, and David Sinclair note that dietary supplementation with cysteine and glycine restores glutathione synthesis and lowers oxidative stress and damage in aging humans.

Rhonda Patrick suggests supplementing with glycine, proline, and hydroxyproline in a 3:1:1 ratio. Andrew Huberman indicates that two grams of glycine and 100 milligrams of GABA taken every third or fourth night can enhance sleep onset and depth.

• 01Increasing glycine intake through sources like bone broth, collagen, gelatin, or glycine powder is reasonable (Peter Attia, Paul Saladino).
• 02Glycine deficiency can be assessed by measuring pyroglutamate, serum/plasma glycine levels, and glutathione levels (Paul Saladino).
• 03Inadequate glycine intake can lead to accelerated aging, reduced skin elasticity and hydration, increased wrinkles, weaker gut lining, slower wound healing, joint and cartilage breakdown, higher oxidative stress, poor detoxification, worse sleep, and increased inflammation (Paul Saladino).
• 04Restricting methionine for longevity is unnecessary; providing sufficient glycine is an alternative approach (Paul Saladino).
• 05Supplementing with glycine, proline, and hydroxyproline in a 3:1:1 ratio yields consistent, measurable benefits across species (Rhonda Patrick).
• 06Sources of glycine include collagenous meat, chewy meat, chuck roast, stew meat, tendons, and bone broth made from tendons or knuckle bones (Paul Saladino).
• 07An excess of methionine without sufficient glycine can be harmful (Paul Saladino).
• 08Excess methionine intake can lead to a loss of glycine (Paul Saladino).
• 09A diet with increased glycine levels can increase healthy lifespan in mice (Paul Saladino).
• 10Dietary supplementation with cysteine and glycine restores glutathione synthesis and lowers oxidative stress and damage in aging humans (Rhonda Patrick, Paul Saladino, David Sinclair).
• 11Glycine is essential during pregnancy for fetal DNA synthesis, increased collagen production, and maternal needs (Paul Saladino).
• 12The alleviating effect of dietary glycine on methionine toxicity is due to the restoration of hepatic glycine levels (Paul Saladino).
• 13Two grams of glycine and 100 milligrams of GABA taken every third or fourth night can enhance sleep onset and depth (Andrew Huberman).
• 14Increasing REM sleep through interventions like injectable pinene and glycine is a positive outcome (Andrew Huberman).

Paul Saladino notes that exclusively plant-based diets may lead to nutrient deficiencies, potentially causing longer healing times due to inadequate glycine or collagen. He also states that excess glycine consumption can deplete methyl groups in individuals with methylation polymorphisms, and a high methionine diet without sufficient glycine can be metabolically stressful. Paul Saladino also suggests that glycine supplementation is not necessary for longevity if sufficient connective tissue is consumed from animal sources. Andrew Huberman warns that taking 60 grams of glycine per day is an extremely high dosage and should not be taken outside of a study. Peter Attia advises avoiding companies that use proprietary blends or nitrogen spiking to artificially inflate protein content.

Rhonda Patrick indicates that larger trials are needed to confirm the benefits of glycine and N-acetylcysteine supplementation in older individuals. Paul Saladino is cautious with glycine intake to avoid methyl group depletion due to MTHFR and taking methylated B vitamins, suggesting that individuals without methylation polymorphisms are unlikely to experience issues with glycine's interaction with methylation. Paul Saladino also notes that the ratio of methionine to glycine is a factor to consider when constructing a carnivore diet. Peter Attia mentions that blood sugar studies were likely conducted with glycine powder, and sleep studies were definitively done with glycine powder.