Rampage is an obvious scam, you need to boost testosterone by 100%+ to see even minimal gains. Just because it's natural doesn't mean it's healthy either.

Of course, you can feel free to post peer-reviewed studies that prove that either a gain in 20-30% of "natural" testosterone increasese amount of muscle mass or gym performance OR a study showing your rampage to increase free testosterone by any relevant amount.

Edit: For pre-workout caffeine is the GOAT.