A breast cancer patient taking both tamoxifen and the GnRH‑analog triptorelin developed extremely high triglycerides and cholesterol, which dropped after stopping the drugs, changing her diet, and starting fenofibrate. This shows that the combination can sharply worsen blood fats, so anyone using triptorelin (or similar hormones) should keep an eye on their lipid numbers and be ready to adjust diet or medication if needed.

Tamoxifen, a selective estrogen receptor modulator (SERM), can have harmful side effects, such as hypertriglyceridemia, which can lead to acute pancreatitis. Meanwhile, triptorelin is an analog of natural GnRH (GnRHa), which may cause a small but significant increase in cholesterol and triglyceride (TG) levels. We describe below the case of a patient with breast cancer treated with Patey's operation, chemo-radiotherapy, and then with tamoxifen and triptorelin. After an exposure period of three months, she presented major hypertriglyceridemia at 56 g/L, total cholesterol at 13 g/L, LDL-cholesterol (LDL-C) at 4 g/L, and HDL at 0.25 g/L. The patient's treatment was stopped by her oncologist. One month after starting an adapted diet and fenofibrate, her TG levels were reduced to 2 g/L. We could confirm from these results that tamoxifen and triptorelin certainly modify lipid metabolism, hence the interest in evaluating the benefit-risk balance and regularly monitoring the lipid profile in order to avoid any fatal complication.