I get little or no sides from tirz or reta, yet sema feels stronger. If you handled tirz fine, reta should probably be okay. Going the other direction sometimes brings more bumps depending on how you bridge the doses.
I'm wondering about a pattern I've noticed in reports, though it might just be stories. Folks mention having no issues with one of these meds and then switching or adding the other without problems either. Obviously individuals vary, but does lack of bad reactions to one suggest you'll handle the second okay too?