Capsules, liquid, or injecting?

So, I’m on TRT with a doc, been using peptides since July. Lifing 4-5 days a week. I started a cycle of s4 capsules 2 weeks ago. Honestly, not sure if it’s working or not tied a new source. I’ve been seeing a lot about rad 140. My questions is, what’s the best route of administration? Is injection IM or subq? Thanks everyone!! Not sure about trusting ChatGPT with these questions😅