l-carnitine davis plus HCA by Activlab at Zumub Carnitine Plus Liquid - Strawberry

The erythropoietin receptor cytosolic juxtamembrane domain contains an essential, precisely oriented, hydrophobic motif

Proc Nutr Soc (2019) 78(1):3444

Another B12 form found in foods is sulphitocobalamin

This approach inspired other programmes: N-hexanoic-Tyr-D-Arg : enkephalin-derived, protease-resistant, studied for pain N-methyl-Aib inclusions : N-methyl substitutions increase membrane permeability at the cost of partial loss of receptor affinity Beta-peptides and D-amino acids : substitution of natural chiral residues by their D enantiomers, making the peptide invisible to endogenous proteases while (sometimes) preserving function Stapled peptides : hydrocarbon cyclisation, popularised by Verdine (Harvard), stabilises alpha helices and improves cellular penetration These strategies progressively shift the peptide / small molecule frontier