It's been studied for decades, and I've never heard of even one case of dangerous side effects like other hormones can have.
It is a non-toxic naturally occurring hormone, not a foreign substance to the body.
It has no drug-like side effects. Hgh injections are a controlled substance available only by prescription.
But as with anything, always consult your physician before taking, especially if you are pregnant, nursing, under the age of 30, or have health problems or concerns.