So 60 mesh works better but still not perfect. Deff drained more overnight but leaving it suspended over the bowl while in vacuum chamber was next level. Basically doubling the surface to draw out solvents, but you do lose some raws that stick to the nylon.
MESO-Rx
Anabolic Steroids
Save your unusable raws Guaranteed.
- Thread starter TheScholarOfBrew
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Thorshammer
Member
This all the way. I stop buying CN crap when I realized they were giving away Eppindorf and Milipore on ebay for pennies on the dollar. Curious how you like that automatic MP analyzer. I kinda like staring at a capillary tube through a magnifying glass till my vision is blurry then trying to read a thermometer lol.
Motojager
New Member
Makes life simple. Set target temp just below and it ramps up slow from there. Accurate and easy to use. And yes just stand back and watch.
So over the last year, I've struggled keeping my CRP in range, couldn't really pin point the source after trying different brands of gear. Been pinning my ethanol re-x test e raws for the last 6 weeks and I finally got my CRP under 3 (sucks it actually dosent give me a true value though). Goes to show me, that there is something in the raws or oils from manufacturers that my body dosent like.
The new raws a virtually PIP less, even with quad shots. Pinning 350mg per week EOD and the recipe below that I feel works the best
250mg/ml concentration
1% BA
0% BB
80% Mig812 or MCT
20% castor
If the carrier oil isent paired correctly with the ester, I feel like the oil might get metabolized faster than the ester, leaving the raws behind in the muscle. Contributing to the pip people experience a day or so after pinning. Idk just my hypothesis
The new raws a virtually PIP less, even with quad shots. Pinning 350mg per week EOD and the recipe below that I feel works the best
250mg/ml concentration
1% BA
0% BB
80% Mig812 or MCT
20% castor
If the carrier oil isent paired correctly with the ester, I feel like the oil might get metabolized faster than the ester, leaving the raws behind in the muscle. Contributing to the pip people experience a day or so after pinning. Idk just my hypothesis
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Thorshammer
Member
Definitely leftovers from esterification with test E not properly manufactured. The oil being absorbed faster than the ester doesn't add up the ough because test cyp is slightly longer and never a problem. The viscosity is plausible though
True, maybe viscosity could be a better way of putting it. There has to be a reason why bayer testoviron depot and rimobolon both use castor oil
Per our almighty grok AI. I guess it just depends on how often you want to Pin. If im EOD, I guess it probably dosent matter
The release rate of a testosterone ester from an intramuscular injection is controlled by two main factors that work together:
The ester itself (its chain length and lipophilicity) → primary driver of half-life
The carrier oil + injection depot physics → secondary but very significant modulator
Here’s exactly how the carrier oil influences release rate control:
1. Diffusion Speed Out of the Oil Droplet
When you inject, the oil forms a depot (a little ball/droplet) in the muscle.
The testosterone ester must diffuse out of that oil droplet into the surrounding tissue fluid before it can be absorbed.
Thinner, low-viscosity oils (ethyl oleate, MCT, grapeseed) → ester molecules move faster through the oil → faster diffusion → quicker release.
Thick, high-viscosity oils (especially castor oil) → ester molecules move extremely slowly through the oil → very slow diffusion → dramatically prolonged release.
This is why Testosterone Undecanoate in castor oil has a half-life of ~34 days in castor oil, but only ~6–8 days when the same undecanoate ester is put into MCT oil in underground lab products.
2. Surface Area of the Depot and Spreading
Thin oils spread out more in the muscle → larger surface area → faster absorption.
Thick oils (castor oil especially) stay as a tight, sticky ball → tiny surface area → extremely slow absorption.
Castor oil is so thick and adhesive that the depot can still be palpated months later in some patients.
3. Polarity and Partition Coefficient
The fatty acid composition of the oil changes how “comfortably” the ester sits in the oil vs. water/tissue.
Castor oil contains ~90% ricinoleic acid (a fatty acid with an —OH group), making it more polar).
This makes the oil “like” the very lipophilic undecanoate ester more than other oils do → the ester partitions very strongly into the oil phase and hates leaving it → slower release.
Cottonseed or grapeseed oil are far less polar → the enanthate/cypionate ester leaves them more easily → faster release.
4. Crystallization Risk vs. Supersaturation
If you tried to dissolve 250 mg/mL testosterone undecanoate in MCT or cottonseed oil, it would crash (form crystals) within days or weeks.
Castor oil is the only oil that can hold that concentration in true solution for years.
So for very long esters, you’re forced to use thick castor oil — the slow release is a “bonus” side effect of the only oil that actually works.
The release rate of a testosterone ester from an intramuscular injection is controlled by two main factors that work together:
The ester itself (its chain length and lipophilicity) → primary driver of half-life
The carrier oil + injection depot physics → secondary but very significant modulator
Here’s exactly how the carrier oil influences release rate control:
1. Diffusion Speed Out of the Oil Droplet
When you inject, the oil forms a depot (a little ball/droplet) in the muscle.
The testosterone ester must diffuse out of that oil droplet into the surrounding tissue fluid before it can be absorbed.
Thinner, low-viscosity oils (ethyl oleate, MCT, grapeseed) → ester molecules move faster through the oil → faster diffusion → quicker release.
Thick, high-viscosity oils (especially castor oil) → ester molecules move extremely slowly through the oil → very slow diffusion → dramatically prolonged release.
This is why Testosterone Undecanoate in castor oil has a half-life of ~34 days in castor oil, but only ~6–8 days when the same undecanoate ester is put into MCT oil in underground lab products.
2. Surface Area of the Depot and Spreading
Thin oils spread out more in the muscle → larger surface area → faster absorption.
Thick oils (castor oil especially) stay as a tight, sticky ball → tiny surface area → extremely slow absorption.
Castor oil is so thick and adhesive that the depot can still be palpated months later in some patients.
3. Polarity and Partition Coefficient
The fatty acid composition of the oil changes how “comfortably” the ester sits in the oil vs. water/tissue.
Castor oil contains ~90% ricinoleic acid (a fatty acid with an —OH group), making it more polar).
This makes the oil “like” the very lipophilic undecanoate ester more than other oils do → the ester partitions very strongly into the oil phase and hates leaving it → slower release.
Cottonseed or grapeseed oil are far less polar → the enanthate/cypionate ester leaves them more easily → faster release.
4. Crystallization Risk vs. Supersaturation
If you tried to dissolve 250 mg/mL testosterone undecanoate in MCT or cottonseed oil, it would crash (form crystals) within days or weeks.
Castor oil is the only oil that can hold that concentration in true solution for years.
So for very long esters, you’re forced to use thick castor oil — the slow release is a “bonus” side effect of the only oil that actually works.
Thorshammer
Member
Why Bayer uses castor oil in Testoviron (Test E/Test P mix) and Rimobolan (Primobolan Depot)Bayer chooses castor oil because it is the only pharmacopeia-approved natural oil with the exact solvent characteristics needed for certain esterified hormones at pharmaceutical concentrations.
Let’s break it down scientifically:
---
✔ 1. Castor oil dissolves certain steroid esters better than other oils
Testosterone enanthate, testosterone propionate, and methenolone enanthate all have:
medium/high hydrophobicity
moderate ester chain length
moderate crystal lattice energy
high melting point relative to shorter esters
Many oils struggle to dissolve these APIs at pharmaceutically acceptable concentrations (e.g. 100 mg/mL, 250 mg/mL) without co-solvents.
Castor oil has:
very high solubilizing power for long-chain esters
higher polarity than MCT or sesame oil (due to ricinoleic acid hydroxyl group)
a unique ability to keep certain steroid esters dissolved at room temp without crashing
excellent thermal stability
This is the single biggest reason Bayer uses it.
They want solubility + stability without needing harsh solvents.
---
✔ 2. Castor oil ensures extremely low injection-site reactions
Because of its viscosity and polarity profile, castor oil:
releases API more slowly
causes less post-injection irritation
reduces “solvent bite”
remains stable in tissue
lowers risk of crystal precipitation in vivo
For Primobolan Depot this is especially important because methenolone enanthate is one of the hardest steroid esters to keep fully dissolved and non-irritating.
---
✔ 3. Castor oil allows Bayer to avoid benzyl benzoate in high amounts
Most underground labs compensate for poor solubility using:
huge benzyl benzoate (BB) percentages
huge benzyl alcohol (BA) percentages
harmful co-solvents
Bayer cannot do that because:
regulated products must minimize BB/BA
they must meet injection comfort standards
they must pass multi-decade stability testing
Castor oil’s solvent power allows minimal co-solvents.
---
✔ 4. Castor oil meets strict pharmaceutical pharmacopeia requirements
Castor oil is in:
USP
Ph. Eur
JP
And is specifically listed for:
long-acting depot preparations
intramuscular oily injections
It:
does not oxidize easily
passes peroxide value tests
remains stable for years
has consistent viscosity under sterile filtration
is compatible with sterilization conditions
This is why every major pharma company uses it for specific esters that need maximum stability.
---
✔ 5. Bayer’s own historic patents mention castor oil’s superior solubility for their chosen esters
Bayer’s original formulation data for:
Testoviron Depot
Primobolan Depot
show that they selected castor oil because it maintained:
clear solution
long-term stability
low crystallization risk
acceptable viscosity for injection
No other oil hit those targets at commercial scale without introducing extra solvents.
---
✔ 6. You can test this yourself:
Methenolone enanthate is extremely difficult to keep dissolved in:
MCT
sesame
grapeseed
cottonseed
But in castor oil, you get:
instant clarity
long-term stability
minimal crash risk
far less co-solvent required
This is why every medical-grade Primobolan formulation in history uses castor oil — including Schering/Bayer.
Thorshammer
Member
Thats hilarious we both ran to AI to find out simultaneously
I think im gonna buy some Mig840 and give that a try as well. I avoided it because of proplene glycol in the description but it looks like thats not exactly the case
Thorshammer
Member
I used to use Mig840 and I still had issues with some batches of test E
What issues were you having?
Thorshammer
Member
Just reports of PIP only certain batches of raws.
If I use straight mct, I noticed more pip with the re-x raws
Thorshammer
Member
Thats because the impurities you removed were acting as co-solvents and the pure raws have lower solubility or thata the only thing that makes sense in my head.
Motojager
New Member
More like removing the impurities aligns the polarity and rids free acids.
Free acid or base forms don’t dissolve well in oil. Also the impurities are more polar. So once you get back to a less polar state, carrier is much more suited. BB normally bridges the polarity gap and masks the impurities. Also getting rid of the residual solvents that were probably in there helps as well.
Flip flop kinetics. Absorption not true elimination drives the apparent elimination rate constant for injectable Test esters.
Call me dumb but I love it in my pharma Test E. Chlorobutanol excipient. No BB. Takes longer to draw and inject but absolutely zero pip.
Less additional excipient you are injecting into your body. For most probably not a huge deal but for some they seem to notice a difference in inflammation / subjective feel /unsure if there is cRP benefit. It ultimately becomes benzoic acid in the body and then metabolized and eliminated.
Benzyl benzoate - Wikipedia
en.m.wikipedia.org
Removing BB from the oil does increase viscosity and slower draw and injection times. BA does influence pharmacokinetics and perhaps BB does as well to some extent. If you sit there and look at Pharma Test Cyp it is 20% BB!
I've recently...
Good info, I'll have to give it a look!Call me dumb but I love it in my pharma Test E. Chlorobutanol excipient. No BB. Takes longer to draw and inject but absolutely zero pip.
Less additional excipient you are injecting into your body. For most probably not a huge deal but for some they seem to notice a difference in inflammation / subjective feel /unsure if there is cRP benefit. It ultimately becomes benzoic acid in the body and then metabolized and eliminated.
Benzyl benzoate - Wikipedia
Removing BB from the oil does increase viscosity and slower draw and injection times. BA does influence pharmacokinetics and perhaps BB does as well to some extent. If you sit there and look at Pharma Test Cyp it is 20% BB!
I've recently...
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