Absorption of Peptides
There is virtually no absorption of peptides longer than four amino
acids. However, there is abundant absorption of di- and tripeptides in
the small intestine. These small peptides are absorbed into the small
intestinal epithelial cell by cotransport with H+ ions via a transporter called PepT1.
Once inside the enterocyte, the vast bulk of absorbed di- and
tripeptides are digested into amino acids by cytoplasmic peptidases and
exported from the cell into blood. Only a very small number of these
small peptides enter blood intact.
Peptide complex A-13 (an extract of the testes of young animals - mature steers) microcrystalline cellulose (E460), lactose, calcium stearate (E470)
Eating testes was attempted in the middle ages. Failed.