Question For Those Backfilling Syringes...

jth0524

Member
This question is for the guys who backfill syringes. How many do you normally backfill at one time? Do you think there’s any concern with the testosterone oil interacting with or eating away at the rubber stopper? Thanks
 
I think some people do it to always have an unused (hasn't penetrated stopper) needle to inject with. For the record, I don't backfill.
 
Many members do backfill syringes, I've never have though. I believe when you backfill a syringe you shouldn't use store it for more than a week. Don't want to inject any bad stuff into your body.
 
I like to backfill because the needle goes in like butter. You can’t feel a thing. Maybe there compromise is to maybe just do 4 at a time. I’m injecting daily so that wouldn’t be too long.
 
This is really trying to just invent a problem where one doesn't exist. How would sterility be affected vs a vial or a syringe. Really. And oil deteriorate a rubber plunger...how would you even come up with such a thing?
 
This is really trying to just invent a problem where one doesn't exist. How would sterility be affected vs a vial or a syringe. Really. And oil deteriorate a rubber plunger...how would you even come up with such a thing?

So many guys try to do exactly that, invent a problem where one doesn't exist.
 
This question is for the guys who backfill syringes. How many do you normally backfill at one time? Do you think there's any concern with the testosterone oil interacting with or eating away at the rubber stopper? Thanks

The amount of benzyl alcohol is minimal and the oil (contains testosterone ester) makes up a majority of volume of the medication and in no way would dissolve the rubber stopper.

Do understand pharmaceutical companies manufacture redi-ject pre-loaded syringes which have been around for years.

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I work on extreme high voltage lines, and the natural rubber line hoses we use for PPE, are quickly degraded by oil based products. Now what oil base, that might be the answer.
 
benzyl alcohol can melt the rubber in the syringe

Pure benzyl alcohol could deteriorate the rubber but the minuscule amount in the oily matrix not a chance.

Pharmaceutical companies have been manufacturing redi-ject pre-loaded syringes for years!

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I work on extreme high voltage lines, and the natural rubber line hoses we use for PPE, are quickly degraded by oil based products. Now what oil base, that might be the answer.

Majority of oils used by pharmaceutical companies for testosterone are food grade but highly purified/refined (cottonseed/sesame/grapeseed) and in no way would degrade the rubber.

All multi-dose vials have a neoprene stopper and even though vials are stored upright, when one is drawing the medication the vial is upside down and the oil comes in contact with the neoprene stopper albeit only for a short time but even after vial is turned back upright the neoprene stopper will have a thin film across it and there is never an issue with deterioration.
 
I guess the best way to know for sure, is to backfill a syringe and just let it sit out for a long time. Watch and see if the rubber deteriorates over time.
 
I’m currently injecting 20mg shallow IM with backfilled 29-30G syringes. I’m going to stick to backfilling a week’s supply at a time based on this thread. Thanks for all of the feedback.
 

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A form of estrogen produced from testosterone. Important for bone health, mood, and libido. Too high can cause side effects; too low can affect well-being.

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Scientific Reference

Lakshman KM, Kaplan B, Travison TG, Basaria S, Knapp PE, Singh AB, LaValley MP, Mazer NA, Bhasin S. The effects of injected testosterone dose and age on the conversion of testosterone to estradiol and dihydrotestosterone in young and older men. J Clin Endocrinol Metab. 2010 Aug;95(8):3955-64.

DOI: 10.1210/jc.2010-0102 | PMID: 20534765 | PMCID: PMC2913038

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