The present invention relates to a conjugate of the formula P-L-I, wherein P is a peptide hormone effecting the metabolism of carbohydrates in vivo, L is a hydrolysable linker molecule consisting of Lp and Li, and I is a molecule capable of inhibiting the effect of the peptide hormone P on the metabolism of carbohydrates in vivo. Under in vivo conditions, the conjugate is the major compound. When the concentration of glucose increases in vivo, the concentration of the peptide hormone effecting the metabolism of carbohydrates in vivo also increases.
