Sounds like bad advice from someone with limited knowledge. No disrespect to your friend, but credentialing to become a trainer doesn't require a lot of knowledge and certainly does not make him an expert like many advanced members here.
Risks to your health are much greater at 20% and above. Have you considered the risks of hypertension, hyperlipidemia, hypercholesterolemia and more at that body fat? You're also likely circulating higher serum estrogen levels elevating immune system risks and prostate diseases if you cycle.
Better safe and healthy than impetuous and injured. Have your "trainer" instruct you on a nutrition and training plan to drop your body fat to 12-15%. If he can't do that, question his integrity as a trainer.
