BACK-FILLING insulin syringes for steroid injections!

DISCLAIMER: Nothing in this article is meant as medical advice. JDB is not a doctor. This article is for entertainment purposes only and no one should try this at home.

So if you frequent the bodybuilding forums and do your research on steroid injections, you may hear about “back-filling insulin pins” to inject with.

Allow me to explain that process to you and why guys do it.


So there is certain gear with a very short half-life that needs to be injected frequently (sometimes daily). It’s not very realistic to be sticking yourself with a larger gauge needle daily, this can create excess scar tissue.

Steroids such as testosterone suspension or Winstrol will need to be injected more frequently. Back-filling insulin syringes is an easier way to do it.

What you want to do is remove the plunger from the insulin syringe. You will draw out your suspension or oil with a larger gauge syringe tip such as an 18 gauge or a 23 gauge.

Once you have 1 ml of oil pulled out (or 1 cc) you simply fill the 1ml insulin syringe up from the back end.

After you fill up the insulin syringe with your compound, you put the plunger back into the syringe and push to remove any air in the front of the insulin syringe.

Congrats, you’re ready to inject a less painful shot on a more convenient and regular basis. I highly recommend this for steroids such as Winstrol, testosterone suspension and Primobolan Depot.


If you don’t know about aspirating a syringe before injecting then you don’t have any business using steroids yet. Go research this first, or better yet pick up a copy Straight from the Underground to learn all about gear and injecting!

So unlike aspirating a normal syringe this will be much more difficult with an insulin syringe. Why? Because insulin pins are only 1 ml and you’re loading 1 ml of oil in most case scenarios.

So there isn’t room to draw back before injecting.

Not to mention, the size of the insulin pin is extremely small and makes this process even more difficult.

So what does that mean for you? It means that places like deltoids, quads and triceps are better injection areas than glutes. You want areas where the skin is thin and there isn’t as much fat to poke through.

The needle you will be using is smaller and shorter, so I wouldn’t inject an area such as my glutes.

When I do Primobolan cycles I’ll back-fill insulin syringes since the molecular weight of Primobolan is so heavy (this is why Primo is most commonly dosed at 100 mg/ml) and I’m trying to get my weekly dosage up to around 500-700 mg or more.

Although it isn’t necessary to inject Primobolan daily because of the half-life of Primo, it is necessary due to a lower dosage per mg with this steroid.

I have found insulin syringes to be a great way to inject frequently without the same discomfort of a larger needle.


This article isn’t for little pussies that don’t like needles. If you’re using 1 injection per week of straight testosterone for a cycle then use a real God damn 3 ml syringe!

This is solely for gear that needs to be injected frequently!

Also know this much; if the gear itself is painful a different sized needle won’t make shit for a difference. If it hurts it hurts… period!

***See below pics for step by step back-fill process***

needle tip removal

Removal of regular 23 gauge needle tip 

18 gauge needle tip

Adding an 18 gauge tip to 3 ml syringe for easy withdrawal of oil

plunger removal slin pin

Removal of plunger from 1 ml insulin syringe

oil withdraw

Withdrawal of gear with 18 gauge tip to 1 ml marker

backfill slin pin

Transferring the gear to the 1 ml insulin syringe from back end of tube

slin pin fill

Putting the plunger back and pushing air out of needle tip, process complete!


So if you’ve been searching around and trying to find the description of “back-filling insulin pins” then hopefully this article helps you out.

If you would like more real, NO-BS info on gear from a guy who knows the deal then be sure to pick up Straight from the Underground, the #1 best underground steroid guide available!

Straight from the Underground ebook


15 thoughts on “BACK-FILLING insulin syringes for steroid injections!”

    • what’s the extent of the injury? Can you not grip? You could always try to do a row with bands around arm or elbow rather than in grip?

        • This is difficult because you’re limited to anything you can use to pull your arm back, however not grab anything, and wrapping something around the wrist is sort of out of the question too. I can think of a couple ways to row using the elbow as resistance and pushing back on something such as a lying leg curl but this is a very difficult injury to work around. If I find anything I’ll pass it on. Maybe look up “amputee exercises” or something along those lines to get some ideas?

      • NJ,the straps go around his wrist, I’m pretty sure we’re assuming this option isn’t available here. The pressure may aggravate the injury further

  1. Steroids ruined my life and I had an experienced “guide” to show me the way.
    The gains are false and stop when you are done using, in fact, you go back to square one.
    I won’t even mention what it does to your body’s ability to produce testosterone.
    It is insanity and unethical to say the least to publish articles that “show” gullible people the way to inject this sh*t.
    Bottom line–you want a great body? It takes years and patience to get one. Use drugs and your body is a fraud just like the top bodybuilders around today who use so many drugs it is mind blowing. They look like cartoon characters not real men. Do a Google search, watch the Youtube interviews and you will see for yourself. See the dozens of people who have had serious health probs or died as a result of using.
    You may publish disclaimers saying you don’t endorse using but your posts say otherwise.
    Anyway, I doubt this will get posted anyway.
    If it does, my message to readers, be a f’ng man, take the long hard road to strength and health.

    • Thanks 4 reading. Hey man, I publish everything, it’s just your opinion and you’re entitled to it. Train hard!! -JD

  2. So ain’t the oil too thick to go through a 31g insulin needle and too short to go into the muscle? So would the oil then sit between muscle and skin ???

    • If you are hitting other muscles besides glutes and you aren’t a fat fuck then you’ll get it in the muscle. Areas like triceps, delts, all day long man! And it’ll be slow to push it out, but doable if you draw up in a different pin and backload the slin syringe. Also, not all slin pins are 31 gauge, some are 29 or 30 gauge.


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