SARMS best dose of S4 for strength?

[Weoasi]

I’m currently 25 years old. I’m 6’1” and I’m around 155 lbs. I’m looking to get stronger. I have a very lean physique and I’ve never been a strong guy. I can only do like 3 or 4 pull ups for example. How much S4 do you recommend that I use? A friend of mine said I can use anywhere from 25 mg up to 100 mg. I want to make sure that I do it an economical way.