If you don't want to rely on supplements or steroids, which both contain adverse side effects, you can still certainly make strong muscle gains by Golgi tendon stimulation.
In order to effectively use this method of training, you must apply one area of the principle of "overload".
Scientific studies reveal that the biggest cause of muscle growth is the activation of the Golgi tendon of the muscle.
So how do you stimulate and overload the Golgi tendon? Imagine that you were laying underneath a car that was elevated on a ramp because it was being worked on. If the elevator device suddenly collapsed or gave out, then you would be forced to do everything in your might to stop the thousand pound vehicle from falling on you. This is a perfect situation for golgi tendon stimulation.
Another example may be if you were in the mountains hiking and a big boulder happened to be in the way of your trail. Instead of going over it, you decide to move it. The movement requires everything you got, all the might you can generate. This is another good example of golgi stimulation.
Now, obviously cars or boulders will not be falling on you in the gym, but if you've followed and understood the concepts and dynamics, it is pretty obvious how you could produce the same effect of such analogies to stimulate natural muscle growth.
The best, safest, and surest way would be to lift heavy weight with the support of a spotter. It is doubtful you'd ever push that car off or move that boulder alone by yourself. So you must test a weight you never lifted before (say for example, on bench you max out at 275 or you 4 rep 250. To get golgi tendon stimulation to trigger growth, either, with the help of a spotter, max out at 280 or 4 rep 260 to failure. Forced reps count. They are exactly the key to growth and using the golgi tendon principle).
Training for strength and growth like this is the best way because you can change the body and generate muscle growth naturally, without relying on steroids or unregulated supplements. And it is guaranteed to work when done properly and followed up with a healthy diet filled with protein and healthy nutrients.