Background:

Telotristat is a tryptophan hydroxylase 1 (TPH1) inhibitor (IC50 = 16 nM).[1] Dietary administration of telotristat to pregnant and lactating mice decreases serotonin levels in maternal serum and decreases the femoral bone volume to tissue volume ratio, trabecular number and thickness, and cortical tissue mineral density, as well as serum calcium levels, in pups.[2]

Reference:
[1]. Goldberg, D.R., De Lombaert, S., Aiello, R., et al. Discovery of acyl guanidine tryptophan hydroxylase-1 inhibitors. Bioorg. Med. Chem. Lett. 26(12), 2855-2860 (2016).
[2]. Weaver, S.R., Fricke, H.P., Xie, C., et al. Peripartum dietary supplementation of a small-molecule inhibitor of tryptophan hydroxylase 1 compromises infant, but not maternal, bone. Am. J. Physiol. Endocrinol. Metab. 215(6), E1133-E1142 (2018).