It's not like aas. It's water based and for me gives no pip whatsoever. It pretty much dissipates instantly. If I had to do even 3ml aas twice daily that would be annoying. But 5ml of synthetine twice daily would genuinely be easy for me in regards to simply taking the shots. Obviously I don't want to be doing 5ml shots twice daily of anything in a perfect world but for fast results and shorter cycles it would be worth it and once I got in routine very easy for me.
I never do sub-q. In my eyes doing anything over 1m sub-q would cause lumping even if it is water based. Some are fine using large amounts sub-q but I would never do it. Just inject it IM. Sometimes I use 30g 1/2 pins which are slin pins so it's not exactly deep and what you call a shallow im injection. I put it in my shoulders most of the time. Basically lean muscle as I use small pins all the time. When I use it next I will use 27g 1/2 and 26g 5/8 pins as that is what I have loads of.
This goes with the above post as well because I could shoot my delts everyday with synthetine if needed as I get no pip. It's not like some aas shots with me and they may hurt slightly or I feel oil the next day. Although you can pretty much shoot anywhere such as delts, chest, lats, quads, arms etc. If shooting glutes I would use a longer pin and they take it easily and are a great place. However for me it tends to be aas in my glutes and synthetine in my delts.