Never do a quad injection.
There are other shot locations that are far better and I'm going to elaborate on why in this article.
More often than not, guys are advised to pin their glutes or quads.
Quads are the absolute worst place to pin in my opinion, and I advise you avoid it like the plague.
While I haven't researched about this specifically, purportedly there are more blood vessels in the quads, which can increase your likelihood of causing hemorrhaging and the build up of a hematoma.
In addition, the quads are very nerve dense and it is far more likely that you will hit a nerve and cause muscle twitching during a quad injection.
Also, if you get post-injection pain (PIP) in your quad, you severely inhibit your ability to function as you need to limp around on your leg and it can significantly impede simple day to day activities.
Sure, you may have injected your quads hundreds of times with no problems.
I had the same experience, I had perfectly sterile oil, perfect shot technique, and still eventually had a shot go awry.
No matter how perfect your shot technique is, how sterile everything is, how perfect everything is laid out in your sequence of events for proper sterile administration, the likelihood that you will eventually have a shot that goes wrong in your quads I believe is much higher than with any other commonly used shot location.
My Quad Injection Mishap
I've never had an infection.
However, I did have one shot in my quad go awry several years ago.
For no good reason at all, my quad started inflating with blood to the point where I needed to get it drained.
There was no abscess, there was no infection.
Clearly I pierced through something that resulted in hemorrhaging, and the build up of a hematoma in my quad.
My leg swelled up with blood to the point where I couldn't even bend it.
My body would have eventually absorbed all that blood and been fine as there was no infection, but the pain was just too intense to deal with, and it would have taken months to drain naturally.
So, I had a slit cut in my upper outer quad and drained the entire thing.
There was so much blood and pressure built up that a projectile bloodstream smashed into the wall across the room after the slit was made in my quad.
Immediately after I had instant relief, and then my leg healed up and was fine.
This was using the exact same sterile testosterone I use for my TRT and there wasn't even an infection.
The technique was also perfect.
There was no good reason for it, my leg just started hemorrhaging from the needle.
Even if you don't have a really bad shot that forces you to make a trip to the hospital, the likelihood is high that you will eventually encounter some level of PIP that cripples you to the point that you can barely walk.
You depend on your legs to walk, and on top of that, it would be wise to avoid injecting areas that could visibly deform you in the first place should you ever encounter a complication or an infection.
This is why I would not inject arms, delts, and after that ordeal, not quads either.
It would be wise to avoid nerve dense muscle groups like the calves entirely as well.
Unless you're pinning 10+ cc's of gear per week, there is no need to even rotate to your quads to begin with in the first place in my opinion.
Choose injection locations that get sufficient blood flow and are the least important areas cosmetically should they get infected or have a complication arise.
Also, they won't prevent you from being able to walk properly if you get a bit of PIP.
The Best Injection Sites
The two best injection sites in my opinion are the glutes and the ventro glutes.
The ventro glute is an area that nobody seems to know about, but it is bar none the best injection site in my opinion.
It is used most often in a clinical setting for intramuscular injections and can handle significantly more oil than most other sites, it gets a lot of blood flow, it is easy to reach if you are heavily muscled and inflexible (unlike the glute), and in general it seems to have the best overall risk profile out of all injection site options.
The easiest way to find this spot is by leaning onto the leg on the side of your body that you're trying to make the ventro glute jut out from.
You'll see the muscle pop out on the side when you put weight on that leg.
For landmarks and a precise way to locate the ventro glute, I advise following the guide in the following video:
The ventro glute is the ideal injection site in my opinion, and it is my main go-to spot for pinning my TRT.
Steer clear of your quads.
It is the absolute last place you should be pinning in my opinion, especially if you pin high volume.
The higher volume you pin, the higher the likelihood of encountering some major issue during a quad injection.
Even if that issue is just PIP, having PIP in your quads that makes you limp isn't something you should ever have to deal with to begin with.