yupp rotate and rotate some more..
speaking from experience when u first start cycling etc.. u will manage to get away with 4 days between sites but that will soon add up and start causing u problems as the years go by..
sites will lose the ability to absorb the depot due to scar tissue build up..and if u continue down this path u may eventually be unable to pin certain sites..
best advice i can give is to pin all sorts of diff sites and to never overload one site with too much oil volume.. and best practice is to have time off or let certain sites time to recover and heal.

I rotate between shoulders and glutes when I used test propionate and winstrol v,every 3 days.

I have a mild sized lipoma on my left delt that my doc says is completely harmless and was probably triggered by some type of trauma.

I can't pin my right delt or glute due to limited range of motion in my left arm from an old collar bone injury. Plus, I was pretty new to the game and didn't have the stomach for pec injections yet.

Long story short I pinned my left delt way too frequently and I think that at least contributed to the formation of the lipoma.

Plus if you hit the same spot too often you will build up a mass of scar tissue that will make pinning more difficult and could slow down oil disbursement.

Best to use as many sites as possible and if you are only comfortable with a few sites stick to long esters.

4-days works for glutes... to say I can do an entire cycle M/F glutes only, but legs, delts, triceps take a good week. It is not really x-number of days, IMO, but when the swelling/lump is gone. I tried early last year to 'work through' the pain of a painful glute injection and only ended up with a 7" long and 4" wide welt that put me out of the gym for three days. Same meds pinned just fine in my quads, delts, just not one on top of an existing welt. Thank God and I'll give Him proper respect on this part, but I have never had an abcess, those are nasty looking and probably life long debilitating. I just finished 8-weekd of ED pinning and that was a bitch, thus the tricep injections, just flat ran out of pin points and winstrol made things double trouble, with painful joints exacerbating pretty intense muscle soreness from fairly large injections. I think as a rule for 'time' between pins, you have to be free of lumps or welts as the body will just compound your bad experience if you try to 'pin thru' the pain.... that pain is telling you something, listen to it.

Not recommended bro I like to have atleast 4 different sites especially with short esters otherwise you are going to feel like a pin cushion. With only 2 sites you have the possibility of getting in to an entire world of troubles I personally like to rotate left delt, right delt, right glute left glute and repeat that way your giving yourself enough time to recover between injections but the more sites you have the better in my opinion. I have never been one for pinning quads due to all the horror stories and nerve endings. If you search through the forums you'll find lots of knowledge and posts over the last few years on multiple injection sites.

I personally would recommend more sites,...... a lot more.

That being said, I inject the same thigh 2 times a week, the difference is volume,...... I only inject 0.3 - 0.4 ml each time (for TRT) of test cyp. Larger volumes of compounds = more recovery time and more scar tissue.