I personally haven't heard of anyone that have had problems with that.
If you get pharm-grade stuff, awesome.
Well with test you're nearly 100% safe if you go with a well-reviewed vendor and lab. I've never heard of fake test in my life. It's the cheapest thing in the world. If anything, some harder to produce compounds are faked with easier to make compounds but the sides you're talking about are coming from the test and anabolics. NOT random shit they would throw in there. If they really wanted to gyp you, they'd put in water or oil. Which would do nothing.
Given that, if you dive into it you should obviously research the possible side effects of certain anabolics in given dosages and then play it smart. I.E., if it's your first time using.. then test only. If you want to try tren, use a little bit of acetate first to see how sides are. Etc.