Long Esters vs Short Esters

/u/Benaoao shared this post which I am drawing from. This was originally published in 2015, and while we have mentioned this in passing in the past, I've wanted to cover it in a little more depth since forever - this article summarizes it well, with only minor edits.

What Is An Ester?

The easiest way to explain an ester is a time release mechanism: the ester prolongs the half-life of the drug. So pure testosterone, or, 'test no ester' is in and out of the system very quickly (less then a few hours). So multiple daily injections would be necessary for stable blood levels. This would obviously be very inconvenient and also very painful, so scientists decided to add a side chain or “ester” to extend the active life of the steroid. As a result, injection frequencies can be cut down. If you look at a picture of testosterone you will see how the molecule has an OH or hydroxyl group at the 17th position. That's necessary for the steroid to bind to the androgen receptor. This is where they add the ester. With this side chain or “ester” blocking the 17th carbon in the beta position, the steroid is temporally inactive. However, as soon as it gets into the blood stream, esterase enzymes come and hydrolyze the ester, or in other words remove the ester, which restores the hydroxyl group making the steroid active. Lastly, the longer the ester, the less water soluble it is and more fat soluble. Something that is more fat soluble is going to take longer be released from the deposit or “depot” the injection creates.

Long esters are more anabolic and will cause more muscle gain

In 1954, a scientist named Reifstein and his team conducted a study comparing Testosterone Enanthate with Testosterone Propionate. The results of these studies were that Test Enanthate resulted in total nitrogen retention of 1.76g/day vs Propionate only 1.02g/day. They also found that the duration of anabolic activity was 33 days with test e and 12 days with prop. These were with the same doses 200mgs of each. Overall, the longer ester retains more nitrogen (muscle gain) per day then short esters, and remains active in the body for much longer. If something causes higher levels of nitrogen retention, and hangs around in your body longer, it's going to be more anabolic.

Plasma levels, suppression, and Estrogen

A study on 3 different testosterone esters, short, medium and long esters: their study showed that the short esters caused the greatest peak plasma levels of testosterone, next highest was the medium and lowest peak was the longest esters. However, they found that the long esters caused the greatest suppression on the gonadal axis and metabolic functions. They even upped the short ester dose by 2-3 times and were still not able to replicate the suppression and metabolic effects of the long esters. This greater suppression is also due to the fact that longer esters convert more readily to estrogen.

I'm sure a lot of you have noticed bloat is greater with long esters. Despite the fact the same people say 'test is test,' we don't typically use short esters for bulks and long esters for cuts. We use short esters for cuts and contest preps because they don't convert to estrogen to the same degree as long esters do, in turn causing less water retention. Estradiol levels were much higher with the group using long esters despite identical doses of the drug. In short, long esters cause a higher rise in estrogen. The study with the 3 different testosterone esters was done over a 28 week period. The shortest esters allowed for the quickest return of natural levels of hormones. Sperm count also remained the highest with the short esters. Concluding that short esters are less suppressible than long esters. Part of the reason why long esters are so much more suppressive is due to the rise in estrogen they cause... the mechanism that tells the HPTA to cease testosterone production is estrogen biding in the hypothalamus. The feedback system thinks 'ok estrogen is binding which is converted from testosterone so this reflects adequate levels of testosterone'. So the HPTA shuts down.

Estrogen and IGF-1 and GH

I’m sure many of you know that using testosterone increases Growth hormone (GH) and Insulin like growth factor-1 (IGF-1) levels to a degree. But did you know that the increase in these hormones are due to estrogen aromatization, [2]? Going back, we know that long esters cause greater increases in estrogen, and estrogen increases GH and igf-1. So using long esters will result in greater muscle gain due to the factors I presented earlier, and also the increase in GH and IGF-1 levels that are much higher when using long esters. And as we all know HGH and IGF-1 are two very anabolic hormones. So higher levels of these hormones means more gains in size and strength.

Is it the same for all steroids with esters?

Nandrolone studies have the same findings as the testosterone esters. The short ester Nandrolone Phenylpropionate (NPP) had greater peak plasma levels then its long estered counterpart. And suppression was greater with the long estered nandrolone deconate (deca-durabolin), and the anabolic effect was greater with the long ester (deca). Most people who have ran both Deca and NPP can say NPP causes less water retention. And the people I've talked to still say Deca is superior for muscle gain despite the same parent hormone, just different ester lengths. So its seems this the ester length and its effects on the drugs behavior remains true among many different hormones.


  • Longer esters cause higher levels of estrogen
  • Longer esters cause more water retention
  • Longer esters cause more suppression of the HPTA
  • Longer esters cause higher levels of nitrogen retention (muscle gain) in other words are more anabolic
  • Shorter esters cause higher peak plasma levels