I would not think size had much to do with side effects. Nor do I think it really pertains to the amount of gear used...although I guess there can be extremes...When you take a 120 pound newbie versus a 300lb vet, then I guess the amount would matter. But in general, I think not. My first cycle was Sust 250 E6D and I grew like a weed and would have did better if my diet had been better. That is the relevant term...DIET!