Study · Amino acids · 2013

Glycine and platelet clumping in rats and human blood

What it found

In rats fed glycine for 5 days, bleeding time doubled and platelet clumping fell by more than half.

Glycine also reduced clumping in human platelets in lab tests.

What they found

Animal and lab studies

Bleeding time in rats

Rats fed 5 percent glycine for 5 days had bleeding time more than twice as long as control rats fed valine. Blood calcium and pH did not change.

Platelet clumping in rats

In rats fed 2.5 or 5 percent glycine for 5 days, the amount of platelet clumping after ADP or collagen was reduced by over 50 percent. Lower doses reduced it less.

Glycine added to rat blood

Adding glycine at 1 to 10 mM to rat blood reduced platelet clumping in a dose-dependent way. At 3 and 10 mM, clumping after ADP fell by about 40 percent.

Strychnine blocks effect

Strychnine, which blocks the glycine receptor, largely prevented glycine from reducing platelet clumping in rat blood. This suggests glycine works through that receptor.

Human platelets in lab

Glycine at 3 and 10 mM significantly reduced clumping of human platelets stimulated with ADP, from control values of 31 to 25 and 22 ohms.

Glycine receptor found

The glycine receptor was detected in platelets from both rats and humans, but not in human red blood cells.

What the authors conclude

“Based on these data, it is concluded that glycine prevents aggregation of platelets in a dose-dependent manner via mechanisms involving a glycine receptor.”
Schemmer P, Zhong Z, Galli U, et al, 2013

Also in their conclusions

  • They conclude that glycine prevents platelet clumping in a dose-dependent way, through mechanisms involving a glycine receptor.
  • They suggest that dietary glycine supplementation should be of immense benefit in preventing diseases where increased platelet clumping and thrombosis are involved.

How it was done

Platelet clumping is involved in heart disease and stroke. The authors wanted to test whether glycine could reduce it, since glycine acts on a receptor found in some white blood cells.

Rats were fed diets with 0.313, 0.625, 1.25, 2.5 or 5 percent glycine for 5 days, while control rats got valine. Bleeding time and platelet clumping were measured. Glycine was also added to rat and human blood samples in the lab.

What it can’t tell you

  • The rat feeding study cannot show whether eating glycine would change bleeding or platelet clumping in people.
  • The human platelet tests were done on blood samples in the lab, not in people, so they cannot show what happens when someone takes glycine.
  • This study did not test whether glycine prevents heart attacks, strokes or other health problems.

The paper

Title
Glycine reduces platelet aggregation
Type
Study
Evidence
Animals and lab studies
Summarised from
Full text
Cite
Schemmer P, Zhong Z, Galli U, et al (2013). Glycine reduces platelet aggregation. Amino acids. doi:10.1007/s00726-012-1422-8Free full textPubMed 23135224DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error