Injection Protocol should be like :

if you dont know how to inject to yourself or didnt try this before then find somebody who can do it until you feel confident and full of knowledge about this subject.
Always use big part of your muscles , and these areas should be away from joints.
For example if you inject to your front part of the leg , then it should at least 20-25 cm upper then your knee cap. Or Triceps ; it should at least 15 cm up and away from elbow to the area where muscle have big mass . Stay way from visible blood vessels.

For Gluteus ( butt ) injection area must be upper part . Imagine like your butt length from down to up is 20 cm or 100%, then you should never inject down 10 cm ( lower 50% ) because thats syatic nerves. Instead of that inject some where between 14-18 cm . Dont go too close to belly also. You can rotate your injections between in that 70-90% from right to left. After you inject you can feel some pain and some swelling thats pretty normal. It can also get a little pink and warm if product is powerful. After that symptoms are gone, touch and feel injection area before you inject again. If its hard inside then normal muscle then dont inject there again until it recovers because if you will inject to an area which didnt recover yet you will have bigger pain and swelling then first injection. It will go like that until that area will get really hard and you will have really hard times when you try to push the liquid inside. That means you should leave that area alone. For example you can rotate in same small muscles. If you have done 1 injection from side of shoulder then for second injection try 3-4 cm back side of shoulder which is also a massive part of the muscle. We advise to waite at least 1 week for injeciton site to recover to inject again.

You need to choose correct needle. Needles longer then 2,5 cm are for gluteus (butt) injections. They are also thicker then small needles. Needles smaller then 2 cm are for site injections (small muscles) .
Before you start; clean your hands , top of the bottle ( rubber stoper) and injection area with alcohol.
Draw desired amount (ml)of liquid to the syringe and send air bubbles back in to glass vial.
Change the needle because needles will lose their their sharpness when you will stick them to rubber stopper which is a hard material. That will cause extra pain in injeciton area
Injection ml will change according to the muscle you are injecting. For small muscles ,
Like Triceps , Shoulders, Biceps ect. 1 ml maximum can be advised. For Legs maximum 1,5 ml and for Gluteus maximum 3 ml can be done. But of course that will change according to the product you will use . Lets say from Ultrabol 225 or Testabolon 400, you cannot inject 3 ml to Gluteus because of the Formula of product. Steroid Kingdom will advise you in this subject if you will ask for help.

After that stick the needle in 1 fast move without hesitation. Draw back the syringe to see if blood fills inside. If blood is coming this means you have hit a blood vessel so you need to take off the needle and find another area.
If everything goes good then start to push the needle softly but with a stable power. You will see liquid will go slowly. Making injections slowly is important because fast injections create more pain the days after that. How slow it must be?. Lets say , at least 10-15 seconds for 1 ml liquid. After the injection is finished take back the needle and put a cotton ball with alcohol immediately. Start to massage slowly for at least 2-3 min. Dont squize your muscle after injection, leave it relaxed when you are massaging . This will reduce the pain.
Steroid Kingdom advises to have your injections before you go to sleep because muscles which are moved after injections will only irritate the injection area and create more pain the other day. Let your muscles relax and consume the product while you are sleeping. Moving the muscles or making a training after injection will make the muscles get full with blood. That blood will push the liquid you have just injected from inside out. According to logic of injection liquid must stay inside deeply muscle, not outside of muscle somewhere close to skin. This will increase swelling and pain .
After you have made all the protocol right and stil having problems with injections, there can be several reasons. 1-The products you are injecting can be too powerful for you. You need to reduce dosages or change products 2- You are not eating good or training good so your body dont go to Anabolism phase so dont create new muscles. When this happens the hormones you are taking from outside will not be needed by body so they will just stay at injection site for longer time and cause problems.