Dynabol® (nandrolone cypionate)

Description:

Nandrolone cypionate is an injectable form of the anabolic steroid nandrolone. This ester provides a pattern of hormone release virtually identical to that of testosterone cypionate, with peak levels of drug being noted approximately 24-48 hours after administration, and a substantial hormone release sustained for about weeks. In this case the active hormone is nandrolone, which is a moderately strong anabolic steroid that carries mild estrogenic and androgenic properties. This product is essentially identical in overall effect to Deca-Durabolin® (nandrolone decanoate), producing measurable gains in strength and lean muscle mass, which tend to be accompanied by a low level of side effects. The one point of difference is that nandrolone cypionate may appear to be a faster-acting compound to some users. Otherwise, there is no discernable difference between the two compounds, and nandrolone cypionate could replace nandrolone decanoate in virtually all cycles.

History:

Nandrolone cypionate was first developed during the 1960’s. It was sold for a brief time as a human-use pharmaceutical, under such brand names as Anabo, Depo-Nortestonate, Nortestrionate, and Sterocrinolo. Such preparations did not last, however, and in recent years the drug has been available only as a product of veterinary medicine. The most notable appearance has come from Jurox in Australia, which marketed a 50 mg/mL version of the drug called Dynabol 50. Jurox also included nandrolone cypionate as part of an anabolic steroid blend called Nandrabolin. Both products, however, were discontinued in 2001, when Jurox scaled back its steroid line. This was likely done in response to media criticisms of heavy Australian veterinary exports to Mexico, which largely fuel the American black market.

The discontinued Jurox products were quickly transferred to SYD Group in Australia, assuring they would not be completely eliminated from commerce. They were subsequently reintroduced to market in 2002, under the names Anabolic DN and Anabolic NA, respectively. The new names made loose reference to the former Jurox trademarks, likely in an effort to retain some of the original market for the products. SYD Group had also introduced a high-dose version of Anabolic DN directly to the Mexican veterinary drug market, but the product has since been withdrawn. This time the product was discontinued following U.S. DEA charges against the firm, alleging that they were conspiring to illegally export Mexican steroids to the U.S. Today, the Anabolic DN and Anabolic NA products remain available on the Australian veterinary drug market, although tight controls limit diversion for off-label use.

How Supplied:

Nandrolone cypionate is available on the Australian veterinary drug markets. It is supplied as 50 mg/mL of steroid dissolved in oil, in a 10 mL vial.

Structural Characteristics:

Nandrolone cypionate is a modified form of nandrolone, where a carboxylic acid ester (cyclopentylpropionic acid) has been attached to the 17-beta hydroxyl group. Esterified steroids are less polar than free steroids, and are absorbed more slowly from the area of injection. Once in the bloodstream, the ester is removed to yield free (active) nandrolone. Esterified steroids are designed to prolong the window of therapeutic effect following administration, allowing for a lessfrequent injection schedule compared to injections of free (unesterified) steroid. Nandrolone cypionate provides a sharp spike in nandrolone release 24-48 hours following deep intramuscular injection, and sustains a substantial release of hormone for approximately 2 weeks.

Side Effects (Estrogenic):

Nandrolone has a low tendency for estrogen conversion, estimated to be only about 20% of that seen with testosterone.1 This is because while the liver can convert nandrolone to estradiol, in other more active sites of steroid aromatization such as adipose tissue nandrolone is far less open to this process.2 Consequently, estrogen-related side effects are a much lower concern with this drug than with testosterone. Elevated estrogen levels may still be noticed with higher dosing, however, and may cause side effects such as increased water retention, body fat gain, and gynecomastia. An anti-estrogen such as clomiphene citrate or tamoxifen citrate may be necessary to prevent estrogenic side effects if they occur. One may alternately use an aromatase inhibitor like Arimidex® (anastrozole), which more efficiently controls estrogen by preventing its synthesis. Aromatase inhibitors can be quite expensive in comparison to anti-estrogens, however, and may also have negative effects on blood lipids.

It is of note that nandrolone has some activity as a progestin in the body.3 Although progesterone is a c-19 steroid, removal of this group as in 19-norprogesterone creates a hormone with greater binding affinity for its corresponding receptor. Sharing this trait, many 19-nor anabolic steroids are shown to have some affinity for the progesterone receptor as well.4 The side effects associated with progesterone are similar to those of estrogen, including negative feedback inhibition of testosterone production and enhanced rate of fat storage. Progestins also augment the stimulatory effect of estrogens on mammary tissue growth. There appears to be a strong synergy between these two hormones here, such that gynecomastia might even occur with the help of progestins, without excessive estrogen levels. The use of an anti-estrogen, which inhibits the estrogenic component of this disorder, is often sufficient to mitigate gynecomastia caused by nandrolone.

Side Effects (Androgenic):

Although classified as an anabolic steroid, androgenic side effects are still possible with this substance, especially with higher doses. This may include bouts of oily skin, acne, and body/facial hair growth. Anabolic/androgenic steroids may also aggravate male pattern hair loss. Women are warned of the potential virilizing effects of anabolic/androgenic steroids. These may include a deepening of the voice, menstrual irregularities, changes in skin texture, facial hair growth, and clitoral enlargement. Nandrolone is a steroid with relatively low androgenic activity relative to its tissuebuilding actions, making the threshold for strong androgenic side effects comparably higher than with more androgenic agents such as testosterone, methandrostenolone, or fluoxymesterone.

It is also important to point out that due to its mild androgenic nature and ability to suppress endogenous testosterone, nandrolone is prone to interfering with libido in males when used without another androgen.

Note that in androgen-responsive target tissues such as the skin, scalp, and prostate, the relative androgenicity of nandrolone is reduced by its reduction to dihydronandrolone (DHN).5 6 The 5-alpha reductase enzyme is responsible for this metabolism of nandrolone. The concurrent use of a 5-alpha reductase inhibitor such as finasteride or dutasteride will interfere with site-specific reduction of nandrolone action, considerably increasing the tendency of nandrolone to produce androgenic side effects. Reductase inhibitors should be avoided with nandrolone if low androgenicity is desired.

Side Effects (Hepatotoxicity):

Nandrolone is not C-17 alpha alkylated, and not known to have hepatotoxic effects. Liver toxicity is unlikely.

Side Effects (Cardiovascular):

Anabolic/androgenic steroids can have deleterious effects on serum cholesterol. This includes a tendency to reduce HDL (good) cholesterol values and increase LDL (bad) cholesterol values, which may shift the HDL to LDL balance in a direction that favors greater risk of arteriosclerosis. The relative impact of an anabolic/androgenic steroid on serum lipids is dependant on the dose, route of administration (oral vs. injectable), type of steroid (aromatizable or nonaromatizable), and level of resistance to hepatic metabolism. Studies administering 600 mg of nandrolone decanoate per week for 10 weeks demonstrated a 26% reduction in HDL cholesterol levels.7 This suppression is slightly greater than that reported with an equal dose of testosterone enanthate, and is in agreement with earlier studies showing a slightly stronger negative impact on HDL/LDL ratio with nandrolone decanoate as compared to testosterone cypionate.8 Nandrolone injectables, however, should still have a significantly weaker impact on serum lipids than C-17 alpha alkylated agents. Anabolic/androgenic steroids may also adversely affect blood pressure and triglycerides, reduce endothelial relaxation, and support left ventricular hypertrophy, all potentially increasing the risk of cardiovascular disease and myocardial infarction.

To help reduce cardiovascular strain it is advised to maintain an active cardiovascular exercise program and minimize the intake of saturated fats, cholesterol, and simple carbohydrates at all times during active AAS administration. Supplementing with fish oils (4 grams per day) and a natural cholesterol/antioxidant formula such as Lipid Stabil or a product with comparable ingredients is also recommended.

Side Effects (Testosterone Suppression):

All anabolic/androgenic steroids when taken in doses sufficient to promote muscle gain are expected to suppress endogenous testosterone production. For sake of comparison, studies administering 100 mg per week on nandrolone decanoate for 6 weeks have demonstrated an approximate 57% reduction in serum testosterone levels during therapy. At a dosage of 300 mg per week, this reduction reached 70%.9 It is believed that the progestational activity of nandrolone notably contributes to the suppression of testosterone synthesis during therapy, which can be marked in spite of a low tendency for estrogen conversion.10 Without the intervention of testosterone-stimulating substances, testosterone levels should return to normal within 2-6 months of drug secession. Note that prolonged hypogonadotrophic hypogonadism can develop secondary to steroid abuse, necessitating medical intervention.

The above side effects are not inclusive. For more detailed discussion of potential side effects, see the Steroid Side Effects section of this book.

Administration (Men):

When used for physique- or performance-enhancing purposes, a dose of 200-400 mg per week is most common, taken in cycles 8 to 12 weeks in length. This level is sufficient for most users to notice measurable gains in lean muscle mass and strength, which should be accompanied by a low level of estrogenic and androgenic activity. Although higher doses (450-600 mg) may produce a stronger anabolic effect, given the relatively low concentration in which this drug is found (50 mg/mL), doses above 400 mg are not commonly applied. Instead, the drug is often stacked with another agent, usually an androgen such as an injectable testosterone, which also helps offset the very low level of androgenicity of nandrolone. An oral steroid with pronounced androgenicity, such as methandrostenolone or oxymetholone, is sometimes used as well, but will also present some hepatotoxicity and have a stronger effect on serum lipids (negatively).

Administration (Women):

When used for physique- or performance-enhancing purposes, a dosage of 50 mg per week is most common. Although only slightly androgenic, women are occasionally confronted with virilization symptoms when taking this compound. Should virilizing side effects become a concern, nandrolone cypionate should be discontinued immediately to help prevent their permanent appearance.

After a sufficient period of withdrawal, the shorter-acting nandrolone Durabolin might be considered a safer (more controllable) option. This drug stays active for only several days, greatly reducing the withdrawal time if indicated.

Availability:

The only remaining pure nandrolone cypionate product is Anabolic DN from Australia, produced only in a 50 mg/ml concentration. It comes in the form of a 10 mL vial, which is contained in an orange tube.

1 Biosynthesis of Estrogens, Gual C, Morato T, Hayano M, Gut M and Dorfman R. Endocrinology 71 (1962):920-25.

2 Aromatization of androstenedione and 19-nortestosterone in human placental, liver and adipose tissues (abstract). Nippon Naibunpi Gakkai Zasshi 62:18-25,1986.

3 Competitive progesterone antagonists: receptor binding and biologic activity of testosterone and 19-nortestosterone derivatives. Reel JR. Humphrey RR, Shih YH, Windsor BL, Sakowski R, Creger PL, Edgren RA. Fertil Steril 1979 May;31(5):552-61.

4 Studies of the biological activity of certain 19-nor steroids in female animals. Pincus G, Chang M, Zarrow M, Hafez E, Merrill A. December 1956.

5 Different Pattern of Metabolism Determine the Relative Anabolic Activity of 19-Norandrogens. J Steroid Biochem Mol Bio 53:255-7,1995.

6 Relative binding affinities of testosterone, 19-nortestosterone and their 5alpha reduced derivatives to the androgen receptor and to other androgenbidning proteins: A suggested role of 5alpha-reductive steroid metabolism in the dissociation of ‘myotropic’ and ‘androgenic’ activities of 19nortestosterone. Toth M, Zakar T. J Steroid Biochem 17 (1982):65360.

7 Metabolic effects of nandrolone decanoate and resistance training in men with HIV. Sattler FR, Schroeder ET, Dube MP, Jaque SV, Martinez C, Blanche PJ, Azen S, Krauss RM. Am J Physiol Endocrinol Metab. 2002 Dec;283(6):E1214-22. Epub 2002 Aug 27.

8 Lipemic and lipoproteinemic effects of natural and synthetic androgens in humans. Crist DM, Peake GT, Stackpole PJ. Clin Exp Pharmacol Physiol 1986 Jul;13(7):513-8.

9 The administration of pharmacological doses of testosterone or 19nortestosterone to normal men is not associated with increased insulin secretion or impaired glucose tolerance. Karl E. Friedl et al. J Clin Endocrinol Metab 68:971, 1989.

10 Influence of nandrolonedecanoate on the pituitary-gonadal axis in males. Bijlsma J., Duursma S, Thijssen J, Huber O. Acta Endocrinol 101 (1982):10812.