Welcome to HCM,
You are taking this supplement but you should find out what are contents of the supplement, if you are in competitive sports your trainer or coach will guide you .
If you have occasional VPCs this should not be cause of concern but if it is more problematic or related to heart defect then it must be investigated by a Cardiologist by EKG,@ Dimensional Echocardiography
, Tread Mill Test and a Hoter Monitoring and if some thing is found abnormal even a Electro physiological study.
If every thing is fine even excess of tea/coffee/energy drinks/smoking
can cause VPCs .
Some times over the counter supplements can have stimulant drugs and even Steroids
which are not advised by doctors until really required.
Please take care