Tribulus supplements are possibly safe for most people when taken by mouth for a short period of time. They have been used safely in research studies lasting up to 8 weeks. The long-term safety of puncture vine is unknown.
Eat the spine-covered fruit of tribulus is likely safe. There has been a report of a serious lung problem linked to eating the fruit.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Taking puncture vine during pregnancy is possibly unsafe. Animal research suggests that tribulus might harm fetal development. Not enough is known about the safety of using tribulus during breast-feeding. It is best not to use tribulus if you are pregnant or nursing.
Prostate problems or prostate cancer: There is a concern that tribulus might make prostate conditions such as benign prostate hypertrophy (BPH) or prostate cancer worse. Developing research suggests that tribulus can increase prostate weight.
Diabetes: Tribulus might decrease blood sugar levels. Dose of diabetes medications might need to be adjusted by your healthcare provider.
Surgery: Tribulus might affect blood sugar levels. This might interfere with blood sugar control during and after surgery. Stop using tribulus at least 2 weeks prior to a scheduled surgery.