Pharmacokinetics and Pharmacodynamics of Steroid Esters

Pharmacokinetics and Pharmacodynamics of Steroid Esters in Oil Vehicle:
Effects of Ester, Injection Site, and Injection Volume

Variations in side-chain ester chemistry are important in the pharmacokinetics of androgen esters in oil vehicle. In humans, the very short propionate (three-carbon aliphatic) ester of testosterone has distinctly shorter duration of action than esters with longer (seven- or eight-carbon) side-chains. More subtle changes in side-chain ester structure have proven ineffective in altering human clinical pharmacokinetics, because substitution of a linear aliphatic side-chain of seven carbons (enanthate) with either a saturated, cyclized, seven-carbon aliphatic chain (cyclohexanecarboxylate) or a linear, aliphatic, eight-carbon chain (cypionate) resulted in virtually unchanged kinetics. (2, 4-6, 12, 15)

Testosterone enanthate (TE) or testosterone cypionate (TC), injected intramuscularly, are the most commonly used androgen preparations with terminal half-lifes of 7-12 days. Pharmacokinetic studies indicate that the major limitations of TE and TC include relatively high peak levels and limited duration of T levels within the normal range (approximately 2 weeks), following an injection. Disadvantages of TE and TC highlighted the need for long-acting preparations of T with more stable delivery kinetics. Testosterone undecanoate (TU; 17-hydroxy-4-androsten-3-one undecanoate) is an unsaturated, aliphatic, fatty acid ester of testosterone (T) in 17β-position. In ampules containing 250 mg of the ester in 2 ml of tea seed oil in administration of 500 or 1,000 mg shows a terminal elimination half-life of 18-23 days. (4, 10, 15, 17)


Testosterone Enanthate
Testosterone Enanthate

Testosterone Cypionate
Testosterone Cypionate

Testosterone Undecanoate
Testosterone Undecanoate

Wider variation in ester side-chain chemistry to include greater chain length and/or aromatic ring structures is a more effective determinant of ester pharmacokinetics. Nandrolone hexoxyphenylpropionate ester has far better depot properties, with a prolonged and retarded release profile, compared with the decanoate (aliphatic chain with 10 carbons). Another study indicates the decanoate (aliphatic chain with 10 carbons) ester has better depot properties than a nine-carbon chain including an aromatic ring. Because the vehicle (arachis oil) was unchanged during this latter study and because of the experimental observation that the oil vehicle influences local reaction to the oil injection, as well as androgen ester pharmacology, these conclusions may be extrapolated to other vegetable oil injection vehicles only with caution. (2, 7, 13, 14, 16)

In addition to the chemistry of the side-chain ester, both injection site and volume can systematically influence blood levels after intramuscular injection of esters in an oil vehicle formulation. Injection site may be important because of differences in tissue composition and blood flow. Intramuscular oil-based injections may more accurately be termed intermuscular or intralipomatous. The former reflects the tendency of oil vehicle to distribute along intermuscular fascial planes, whereas the latter depends upon the amount of fat at the injection site (including systematic gender differences) together with needle geometry and anatomy of the injection depot. Intralipomatous deposition of injections with a larger vehicle volume may explain the slower release kinetics of nandrolone decanoate in the gluteal region, as well as the differences from the deltoid site, which has a lower fat content. (1, 13)



Nandrolone Decanoate

Nandrolone Decanoate

Nandrolone Phenpropionate (NPP)

Nandrolone Phenpropionate (NPP)

Nandrolone P-Hexoxyphenylpropionate

Nandrolone P-Hexoxyphenylpropionate

There is a rapid and dose-proportional increase in nandrolone serum levels across a dose range after a single intramuscular injection of 50–150 mg nandrolone decanoate in healthy young men with peak serum levels of nandrolone reached 2–3 d after injection. Subsequently, nandrolone levels decreased, but were still measurable 32 d after dosing in approximately half the subjects in the 50-mg group and in all subjects in the 100- and 150-mg groups. The half-life ranged from 7.1 days – 11.8 days. In addition, urinary metabolites 19-NA and/or 19-NE were detectable for up to 6 months after the 100 and 150 mg injection in a significant proportion of subjects. (2)

 Nandrolone Profile

Mean serum concentration profiles for nandrolone after single gluteal muscle injection in 1 ml arachis oil of 50, 100, or 150 mg nandrolone decanoate in healthy men.

Nandrolone displays so-called flip-flop pharmacokinetics, which means that the ascending phase of the curve represents the disposition of nandrolone and the descending part of the curve represents the rate-limiting process of release of nandrolone decanoate from the muscle into the general circulation. The half-life in the descending phase of the curve is an estimate of the absorption half-life rather than the elimination half-life. (2)

In the following study, 23 healthy men were randomized into four groups receiving a single dose of 100 mg nandrolone esters: nandrolone phenylpropionate in 4 ml arachis oil injected into the gluteal muscle (group 1), nandrolone decanoate in 4 ml arachis oil injected into the gluteal muscle (group 2), nandrolone decanoate in 1 ml arachis oil injected into the gluteal muscle (group 3), or nandrolone decanoate in 1 ml arachis oil injected into the deltoid muscle (group 4). Absolute bioavailability was higher after single-dose injection of 100 mg nandrolone decanoate in 1 ml arachis oil into the gluteal muscle (73%) than in the other three groups (53–56%). (8)


Nandrolone Concentrations

Time course of plasma nandrolone concentrations in 23 healthy men over 32 days after intramuscular injection of 100 mg of nandrolone phenylpropionate in 4 ml of arachis oil vehicle into the gluteal muscle (group 1) () or injection of 100 mg of nandrolone decanoate into the gluteal muscle in 4 ml of arachis oil vehicle (group 2) (?), into the gluteal muscle in 1 ml of arachis oil vehicle (group 3) (•) or into the deltoid muscle in 1 ml of arachis oil vehicle (group 4) (?). Results are expressed as mean and S.E.M., unless the S.E. is smaller than symbol. (8)

Corresponding to the patterns of blood concentrations, pharmacodynamic indices reflecting androgen-induced inhibition of pituitary-testicular function, namely blood testosterone and inhibin concentrations, are also systematically influenced by these factors. Testosterone and inhibin concentrations represent effective markers of endogenous pituitary gonadotropin (LH and FSH, respectively) secretion. This reflects the physiological fact that pituitary LH acts exclusively upon testicular Leydig cells, due to their unique expression of cell surface membrane LH receptors. In healthy men, virtually all circulating testosterone originates from Leydig cells, with an absolute requirement for trophic influence from LH derived from the bloodstream. Similarly, pituitary FSH acts exclusively upon testicular Sertoli cells, which uniquely express FSH receptors on their cell surface membranes, and virtually all circulating immunoreactive inhibin originates from the gonads. As a result, blood levels of these two hormones are useful integrated bioassay indicators of endogenous pituitary gonadotropin secretion, as reflected by the testicular hormonal response to ambient blood LH and FSH levels. These two pharmacodynamic indices show physiologically meaningful distinctions between the esters and the effects of injection site and volume. (8, 9, 11)


Testosterone Concentrations

Time course of plasma testosterone concentrations in 23 healthy men over 32 days after intramuscular injection of 100 mg of nandrolone phenylpropionate in 4 ml of arachis oil vehicle into the gluteal muscle (group 1) () or injection of 100 mg of nandrolone decanoate into the gluteal muscle in 4 ml of arachis oil vehicle (group 2) (?), into the gluteal muscle in 1 ml of arachis oil vehicle (group 3) (•) or into the deltoid muscle in 1 ml of arachis oil vehicle (group 4) (?). Results expressed as mean and S.E.M., unless the S.E. is smaller than the symbol. (8)

The pharmacodynamic variability in plasma testosterone and inhibin concentrations is accounted for by the variability between esters and the site and volume of injection of the nandrolone injections. The overall kinetics of suppression of testosterone is dominated by the slow negative feedback system, rather than the much faster metabolic clearance of testosterone. This negative feedback is mediated via inhibition of pulsatile gonadotropin-releasing hormone secretion from hypothalamic neurons into the pituitary portal system and then pituitary LH secretion from gonadotropes. This is in stark contrast to a highly potent and specific gonadotropin-releasing hormone antagonist that causes immediate cessation of gonadotropin-releasing hormone action leading to castrate testosterone concentrations within 12 hr, compared with 5 to 10 days with AAS administration. After a single 100 mg injection of NPP, recovery takes 10+ days. After ND, recovery takes 15+ days. It is important to note these are single administrations of 100 mg. HPTA recovery with repeated doses of 200+ mg is long!!!! (3, 8)

Administration of androgens such as testosterone and 19-nor-testosterone has been most frequently via depot intramuscular injections of steroid esters dissolved in a vegetable oil vehicle. Intramuscular injections provide sustained androgen release into the circulation and remain the mainstay of androgen replacement therapy. Experimental studies suggest that absorption rates are predicted by the oil/water partition coefficients (or hydrophobicity) and that the oil vehicle is absorbed more slowly than the androgen ester, with gradual release into the extracellular fluid, where esters are rapidly hydrolyzed to liberate biologically active steroid. As the above shows, other factors influence steroid appearance in the bloodstream that include the chemistry of the side-chain ester (hydrophobicity, steric hindrance of hydrolysis, and solubility), as well as injection factors (technique, depth, site, volume, Ph, and osmolarity of the solution).

 1.                  Al-Hindawi MK, James KC, Nicholls PJ. Influence of solvent on the availability of testosterone propionate from oily, intramuscular injections in the rat. J Pharm Pharmacol 1987;39(2):90-5.

2.                  Bagchus WM, Smeets JMW, Verheul HAM, De Jager-Van Der Veen SM, Port A, Geurts TBP. Pharmacokinetic Evaluation of Three Different Intramuscular Doses of Nandrolone Decanoate: Analysis of Serum and Urine Samples in Healthy Men. J Clin Endocrinol Metab 2005;90(5):2624-30.

3.                  Behre HM, Klein B, Steinmeyer E, McGregor GP, Voigt K, Nieschlag E. Effective suppression of luteinizing hormone and testosterone by single doses of the new gonadotropin-releasing hormone antagonist cetrorelix (SB-75) in normal men. J Clin Endocrinol Metab 1992;75(2):393-8.

4.                  Behre HM, Nieschlag E. Testosterone buciclate (20 Aet-1) in hypogonadal men: pharmacokinetics and pharmacodynamics of the new long-acting androgen ester. J Clin Endocrinol Metab 1992;75(5):1204-10.

5.                  Belkien L, Schurmeyer T, Hano R, Gunnarsson PO, Nieschlag E. Pharmacokinetics of 19-nortestosterone esters in normal men. J Steroid Biochem 1985;22(5):623-9.

6.                  Fujioka M, Shinohara Y, Baba S, Irie M, Inoue K. Pharmacokinetic Properties of Testosterone Propionate in Normal Men. J Clin Endocrinol Metab 1986;63(6):1361-4.

7.                  Khankhanian NK, Hammers YA, Kowalski P. Exuberant local tissue reaction to intramuscular injection of nandrolone decanoate (Deca-Durabolin)–a steroid compound in a sesame seed oil base–mimicking soft tissue malignant tumors: a case report and review of the literature. Mil Med 1992;157(12):670-4.

8.                  Minto CF, Howe C, Wishart S, Conway AJ, Handelsman DJ. Pharmacokinetics and pharmacodynamics of nandrolone esters in oil vehicle: effects of ester, injection site and injection volume. J Pharmacol Exp Ther 1997;281(1):93-102.

9.                  Nieschlag E, Cuppers HJ, Wiegelmann W, Wickings EJ. Bioavailability and LH-suppressing effect of different testosterone preparations in normal and hypogonadal men. Horm Res 1976;7(3):138-45.

10.              Schubert M, Minnemann T, Hubler D, et al. Intramuscular testosterone undecanoate: pharmacokinetic aspects of a novel testosterone formulation during long-term treatment of men with hypogonadism. J Clin Endocrinol Metab 2004;89(11):5429-34.

11.              Schulte-Beerbuhl M, Nieschlag E. Comparison of testosterone, dihydrotestosterone, luteinizing hormone, and follicle-stimulating hormone in serum after injection of testosterone enanthate of testosterone cypionate. Fertil Steril 1980;33(2):201-3.

12.              Schurmeyer T, Nieschlag E. Comparative pharmacokinetics of testosterone enanthate and testosterone cyclohexanecarboxylate as assessed by serum and salivary testosterone levels in normal men. Int J Androl 1984;7(3):181-7.

13.              Tanaka T, Kobayashi H, Okumura K, Muranishi S, Sezaki H. Intramuscular absorption of drugs from oily solutions in the rat. Chem Pharm Bull (Tokyo) 1974;22(6):1275-84.

14.              van der Vies J. Implications of basic pharmacology in the therapy with esters of nandrolone. Acta Endocrinol Suppl (Copenh) 1985;271:38-44.

15.              Weinbauer GF, Partsch C-J, Zitzmann M, Schlatt S, Nieschlag E. Pharmacokinetics and Degree of Aromatization Rather Than Total Dose of Different Preparations Determine the Effects of Testosterone: A Nonhuman Primate Study in Macaca fascicularis. J Androl 2003;24(5):765-74.

16.              Wijnand HP, Bosch AM, Donker CW. Pharmacokinetic parameters of nandrolone (19-nortestosterone) after intramuscular administration of nandrolone decanoate (Deca-Durabolin) to healthy volunteers. Acta Endocrinol Suppl (Copenh) 1985;271:19-30.

17.              Zhang GY, Gu YQ, Wang XH, Cui YG, Bremner WJ. A pharmacokinetic study of injectable testosterone undecanoate in hypogonadal men. J Androl 1998;19(6):761-8.

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Who is Primordial Performance?

Who We Are –

We realize that starting a supplement company really isn’t that special. 

Any person with a couple thousand bucks could start a supplement company in their garage if they wanted too. These are the same companies that grab the cheapest powders they can possibly find from China and throw them into capsules and tubs. This type of company usually has zero testing , QC or understanding of their products – and when something goes wrong it gives the entire industry a bad name. 

We are the people who would go broke and run ourselves out of business to produce quality at all costs. In fact, as I write this, we are sitting several hundred thousand dollars in the hole – all because we invested every last cent into making the AndroSeries (and past projects) the best we possibly could.

We stick to the highest quality ingredients and stay mindful of the important things: identity, purity, natural, organic**, kosher, sugar free, pesticide free, heavy metal free, etc.

** Not everything we sell is organic, but when we can, we do.

At least you will know that if we go out of business it wasn’t from bad products – it would be from an obsession with only providing the greatest.

Here are some things we are proud of –


  • Producing the industry’s highest quality steroid products since 2006
  • “A” rating with the Better Business Bureau (BBB)  Better Business Bureau
  • Up to a 150% Money Back Guarantee (w/ less than 0.1% return rate)
  • More than 25% customer loyalty (multiple purchases)
  • Nominated for new brand of the year by


  • Sponsoring and contributing to over 12 major bodybuilding and health fitness forums

Technological Achievements

  • Liqua-Vade HTC (2011)
  • Liqua-Vade Oral Delivery System (2009)
  • OHV Topical Delivery System (2006)

Products of Passion –

We take our work very seriously. 

Everything we do is dedicated to making the best and then making it even better.

We are on top of the research, technology and quality. We are real people who live and breathe to bring you legal and natural steroid hormones, amino acids, phyto-nutrients and other cool nutraceuticals.

We put great craftsmanship into the design of our products. Each and every product is backed by 100’s of hours of heart and soul. 

Custom Manufacturing –

Our in-house manufacturing facility allows us to have tight control of our quality, while giving us the ability to produce high-end specialty formulations and rapid product improvements.

In case you’re wondering why our products are more expensive than our nearest competitor, it’s because the raw cost of our products exceeds the norm by about 3-4 times – and for good reason.

For instance, the cost on our AndroMass just in raw materials is $57.00. That’s unheard of in this industry. Maybe it’s nothing to be proud of, but at least you know you get what you pay for. 


Other Companies Primordial Performance
Average $4.00 cost Average $15.58 cost
Average $35.00 retail Average $39.80 retail

Our Relationship with YOU –

We have a love/hate relationship with our customers.

We hate it when our customers make us work so hard – always wanting the latest and greatest and wanting it delivered fast which means we will always be a slave trying to fulfill great expectations. 

But we love the customer when we get an email like this –

"I just want to thank Primordial Performance for producing the best products in the industry which have completely transformed my body. Your customer service, educational info and dedication to quality is second to none. My life is changed and I owe it all to you guys. Thank you."

This makes it all worthwhile – the 90hr work weeks, the formulation challenges, the financial struggles, and the demanding and angry customers.

Door Wide Open –

Right now, you could get on our forum and give your full honest opinion of Primordial Performance – good or bad – and anybody can read it.

And as long as you don’t completely spam our forum with overt pornography and profanity you can say whatever you like — We have a non-censor policy because we only want real honest feedback on our forums.

Have a comment, question or complaint?

Just call, email or jump on live chat – we are always available.

Heck you could even stop by our facility.***

*** We charge $10/person to see the genetic monster Matt Porter live and in-person.

Invest in Us –

Your support and repeat business allows us to continue bringing out excellent products.

The profit we make from our sales goes right back into R&D, educational material, superior customer service, and infrastructure improvements. 

Our goals have been, and always will be –

  1. To make sure you love our products.

    We understand that word of mouth is still king. The more you love our products, the more likely you will tell your friends and family and continue to buy from us. We understand that your satisfaction is the very core of our business, and we hold it in the highest regard.

  2. To become your #1 source for hormone supporting products.

    We strive to provide the best steroidal and hormone optimizing products – with quality that you can trust.

  3. To bring you safe and honest advice.

    We seek out the most knowledgeable representatives and customer service agents to make sure you get good honest advice – even if it doesn’t involve buying our products. 

Eric Potratz, The Early Days – 

To understand the company’s mission, it’s important to understand my personal mission – 

My passion for the science and development of hormone based products started many years ago. I was a local consultant and frequent user of the original pro-hormones that were released in the late 1990’s, and eventually the methylated oral steroids that started to appear on the supplement market in 2003. 

At the time. I personally felt immune to the side effects even though I was educated on them and warned others about them. I was big, strong and fearless – because that’s the way steroids make you feel.

After several years of cycling and hearing the scrutiny from my mother I figured I would get a quick health screening, just to prove that I was healthy and there was nothing to be concerned about.

In 2004, I visited a local pharmacy for a basic cholesterol screening. I was aware of the fact that methylated steroids where bad on cholesterol levels, so I decided to check my cholesterol and really put my health to the test. I really didn’t expect the results to be too bad; after all, I was taking my fish oil.

What happened next was a crystalizing moment for me –

 "Mr. Potratz, your results are in" – said the pharmacist.

She continued…

"We are very concerned about the results. I have never seen this before, but your HDL values where undetectable and your LDL is over 190. This puts you at a very high risk of heart disease. Whatever you are using, you need to stop using, because it’s going to give you a heart attack."

Diet, exercise and fish oil weren’t going to fix this problem – I was already eating clean and working out daily. The methylated steroids essentially ruined my cholesterol levels. I immediately realized it was time to get off.

I got started right away on my post cycle therapy (PCT). Back then, estrogen was considered the evil culprit and SERM’s were considered the only way to recover so I started taking Clomid and various anti-estrogens over the course of the next few months in an attempt to get my testosterone levels back up. Anti-estrogens like ATD, 6-OXO, and formestane were popular for their supposed ability to crush estrogen levels – but as I would learn, these were very poor methods for PCT. 

After several months on the above protocol, things only got worse…

I started noticing that my erections weren’t as hard, and my sexual desire and sensitivity was lacking, and my cholesterol values were not recovering. I also found myself emotionally unstable – presumably from the Clomid. This basically wrecked my sex life. Impotence in your early 20’s is like getting a cancer diagnosis. It feels like your life is over.* 

Over the course of all this, I learned two important things –

1. It’s easy to assume that most steroids are safe because most side-effects aren’t obvious. 

2. Not all steroids are created equal. Methylated steroids are unnatural and much more dangerous than naturally occurring steroids. I decided to dedicate my life to designing safer and smarter steroids (and better methods to recover from steroids)

Thus in 2006, Primordial Performance was born, debuting the safe and natural topical steroid formula Dermacrine –

*Don’t worry, the impotence is gone now.

Ghrelin Hormone: An Ectomorph’s Solution to Muscular Weight Gain

The endogenous growth hormone secretagogue Ghrelin may play a paramount role in your quest for muscle growth. This gastric hormone stimulates hunger in mice and in humans by binding to the ghrelin receptors located in the hypothalamus and the hippocampus.

Reasons why people feel the urge to eat

Ghrelin is highest when blood sugar is low and being in a fasted state. Ghrelin is a potent endogenous growth hormone releaser, and is the strongest of the secretagogues. Even though it increases growth hormone release, some of its effects are quite different from growth hormone itself. Ghrelin encourages lipogenesis, whereas growth hormone supports lypolysis. Ghrelin also supports glucose oxidation, while growth hormone suppresses insulin production for inhibited glucose disposal. This equates to ghrelin being highly effective for weight gain through adipogenic pathways and growth hormone supporting weight loss through lipolytic pathways.

Ghrelin Effects:                                            Synthetic Growth Hormone Effects:

-Increases endogenous GH                                -Synthetically derived

-Encourages lipogenesis (fat gain)                     -Encourages lipolysis (fat loss)

-Increases glucose oxidation                             -May promote insulin resistance

-Great for weight gain                                       -Great for fat loss

Knowing such facts makes it very clear that ghrelin would be perfect for the ectomorphic, hard gainer body type. If you are someone who frequents the bodybuilding internet forums, then you are probably aware of the recent surge in popularity with research peptide companies. These companies sell a product called GHRP-6, which is a hexapeptide comprised of 28 amino acids that signals the pituitary to secrete growth hormone through increasing ghrelin production. Using GHRP-6 in conjunction with a regimented weight training program and a meticulously planned diet, the ectomorphic trainee could consume copious amounts of high quality nutrients to achieve muscular weight gain that once seemed impossible.

– I must  mention one must be very stringent and meticulous with whom they decide to research with, meaning make sure the company is of high quality and the peptides are USA grade ingredients. A company such as Southern Research Co. has a trusted reputation and  is held in high regard in the research peptide community. 



1.) Cordido, Fernando; Isidro, Maria L.; Nemina, Rosa; Sangiao-Alvarellos, Susana, Ghrelin and Growth Hormone Secretagogues, Physiological and Pharmacological Aspect. Volume 6, Number 1, March 2009 , pp. 34-42(9)

2.) .Cummings DE, Weigle DS, Frayo RS, Breen PA, Ma MK, Dellinger EP, Purnell JQ, Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery.
N Engl J Med. 2002 May 23;346(21):1623-30.

3.) Britt Edén Engström, Pia Burman, Camilla Holdstock and F. Anders Karlsson,
Effects of Growth Hormone (GH) on Ghrelin, Leptin, and Adiponectin in GH-Deficient Patients. The Journal of Clinical Endocrinology & Metabolism Vol. 88, No. 11 5193-5198

The best muscle building protein drink available

After siphoning through several research papers and experimenting with numerous protein formula’s I found the answer…

 “What is the best protein drink for gaining muscle?”

I will briefly go over the common protein powder sources that are highly available and readily used by most health and fitness enthusiast. I WILL NOT expand too much on each type of protein as this article isn’t a long winded “fact sheet.”

Most people involved in the health/fitness and Bodybuilding industry are all too familiar with whey protein, namely whey protein concentrate (WPC) & whey protein isolate (WPI). Both of these whey proteins are considered “fast digesting” and have a high biological value (91). WPI & WPC are typically used pre & post training or anytime someone needs a fast and efficient protein source in their body.

Also highly sought after are the “slower digesting proteins” such as calcium caseinate and micellar casein, with a slightly lower biological value than WPI &WPC (77). These milk proteins are highly regarded as “night time” protein for their slow and steady amino acid delivery.

Recently, peptide based proteins have generated a lot of buzz due to their potential to be rapidly taken up into the blood stream, virtually by-passing the digestion process.Whey protein hydrolysate and casein hydrolysate (PeptoPro) are the 2 proteins that fall into this category. These hydrolyzed versions of whey and casein contain fragments of protein chains composed of 2-3 amino acids (di, tri & oligo) which are instantaneously absorbed and elevate blood
amino acid levels sky high.

A recent study compared both whey and casein and their effects on muscle protein synthesis (MPS) following resistance training.

The study used 17 healthy, young males as test subjects. They were devoid of medical ailments and were all in great physical condition. The subjects were randomized to participate in either 2 protein trials in randomized order or one control trial. protein trial group, 9 men and control trial group, 8 men.

The subjects came into the test facility all in a fasted state and underwent heavy resistance training consisting of 10 sets of 8 repetitions at a predetermined load corresponding to 80% of 1RM.

Post exercise, (within 5 minutes) the participants consumed either water, casein or whey protein.

The amount of protein ingested was 20 grams dissolved into 400 ml of water.

Some cool observations were notated –

Researchers found that whey protein –

  • Spiked IGF-1 concentrations instantly and peaked at 30  minutes
  • Spiked insulin concentrations from 15 – 60 minutes
  • Elicited a Stronger myofibrillar FSR increase immediately post exercise
  • Induces a stronger protein synthesis response in the early post workout period compared to casein

Researchers found that casein protein

  • Did not have profound effects on insulin release
  • Elevated myofibrillar FSR steadily over 6h period opposed to whey
  • Had better anti-catabolic effects than whey protein

On a side note:

The same study did touch base on some fascinating information regarding micellar casein and whey & casein hydrolysates.

Whey hydrolysate elicited an even greater initial spike in muscle protein synthesis FSR than regular whey.

Micellar casein elicited an even slower and longer lasting muscle protein synthesis FSR compared to regular casein.

The very slow micellar casein and the very fast casein hydrolysate (PeptoPro) results in SIMILAR muscle protein synthesis response in the 6h postprandial period, with the casein hydrolysate having the largest MPS response in the early stages.

The conclusion of the study was obvious in the fact that whey initially
spiked MPS immediately and then quickly plummeted downward after the initial spike,
casein spiked MPS more moderately with a more prolonged elevation as time
passed. Immediate intake of whey and casein following heavy resistance training
in young men results in SIMILAR MPS response over the subsequent 6-h recovery

Now – Back to the question of “What is the best protein drink for gaining muscle?”

From my research and personal, empirical experience I believe it is in one’s best interest to utilize a protein supplement that contains a ratio of 50% cold-filtered whey protein isolate & 35% micellar casein or Australian caseinate, and 15% hydrolyzed whey peptides.

Combining both FAST and SLOW assimilating, high quality protein sources have yielded the best results for not only me, but clients as well. You get the benefit of initial high blood amino acid levels and insulinogenic response from whey protein isolate & hydrolyzed whey peptides, then the micellar casein or Australian caseinate sustains blood amino acid levels for up to 7 hours, which elicits an anti-catabolic effect.

Australian Casein Benefits
  • Superior Amino Acid Profile compared to regular casein
  • Higher Glutamine Content compared to regular casein
  • 4.5% Higher Protein Content compared to regular casein
  • Superior Solubility compared to regular casein (mix with a spoon)

I also find it advantageous to consume casein hydrolysate (PeptoPro) DURING your training session to keep blood amino acid levels elevated while not disrupting your gastro-intestinal tract, due to peptide proteins being pre-digested.


1.    Calbet JA, Holst JJ. Gastric emptying, gastric secretion and enterogastrone response after administration of milk proteins or their peptide hydrolysates in humans. Eur J Nutr. 2004 Jun;43(3):127-39. Epub 2004 Jan 6.

2.    Koopman R, Crombach N, Gijsen AP, Walrand S, Fauquant J, Kies AK, Lemosquet S, Saris WH, Boirie Y, van Loon LJ. Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein. Am J Clin Nutr. 2009 Jul;90(1):106-15. Epub 2009 May 27.

3.    Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol. 2009 Sep;107(3):987-92. Epub 2009 Jul 9.

4.     Paul J. Cribb; Andrew D. Williams; Michael F. Carey; Alan Hayes Full Article Table of Contents for Vol. 16, Iss. 5 The Effect of Whey Isolate and Resistance Training on Strength, Body Composition, and Plasma Glutamine.  IJSNEM, 16(5), October 2006, Copyright © 2006

5.     Beelen M, Koopman R, Gijsen AP, Vandereyt H, Kies AK, Kuipers H, Saris WH, van Loon LJ. Protein coingestion stimulates muscle protein synthesis during resistance-type exercise. Am J Physiol Endocrinol Metab. 2008 Jul;295(1):E70-7. Epub 2008 Apr 22.


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