Nandrolone Decanoate Injection

Nandrolone decanoate is an intramuscular depot form of nandrolone, acting as a prodrug that slowly releases nandrolone into circulation. Nandrolone is an agonist of the androgen receptor (AR) in target tissues, which may lead to increased protein synthesis, enhanced nitrogen retention in muscle, and stimulation of erythropoiesis (red blood cell production). These actions underlie its anabolic effects, such as promoting muscle growth, bone density, and red cell mass, which may be beneficial in catabolic states.^[1]^[5]

Compared to endogenous testosterone, nandrolone exhibits a higher ratio of anabolic-to-androgenic activity, meaning it tends to favor muscle and bone-building effects over masculinizing effects. This pharmacologic profile is partly due to nandrolone’s unique metabolism: it is less readily converted to the potent androgen dihydrotestosterone (DHT) in androgen-sensitive tissues, resulting in relatively reduced AR stimulation in tissues like skin and prostate. Instead, 5α-reductase enzymes convert nandrolone to a weaker androgen (dihydronandrolone), which may contribute to a lower incidence of certain androgenic side effects (e.g. scalp hair loss or prostate enlargement) as compared to testosterone.^[1]^[5]

Nevertheless, complete dissociation of anabolic and androgenic effects has not been achieved – nandrolone can still cause androgenic effects in the body. It may suppresses the hypothalamic–pituitary–gonadal axis via negative feedback, leading to reduced gonadotropin secretion and a consequent decline in endogenous testosterone and sperm production.^[1]^[5]

The decanoate ester confers a prolonged duration of action: following intramuscular injection, nandrolone decanoate is slowly absorbed and hydrolyzed, with an effective half-life of about 6–12 days and activity that may persist for 2–3 weeks. Pharmacologically, it has minimal estrogenic activity (it can aromatize to estradiol to a small extent) and does possess some progestogenic affinity, which together can contribute to effects like fluid retention and changes in lipid metabolism.^[1]^[5]

In summary, nandrolone decanoate’s mechanism is similar to that of other anabolic steroids – binding AR to exert tissue-building effects – but its kinetic profile and metabolism grant it a distinctive balance of potent anabolic efficacy with comparatively reduced (but not absent) androgenic and estrogenic side effects. All such effects are dose-dependent, and higher doses or prolonged use will increase the likelihood of androgenic and metabolic side effects.^[1]^[5]

Androgens like nandrolone can interact with other medications and may also alter certain laboratory test results.

Anticoagulants: Anabolic steroid therapy can enhance the anticoagulant effects of oral anticoagulants (such as warfarin) by mechanisms that are not fully understood, potentially increasing sensitivity to these drugs. Patients on warfarin or similar anticoagulants may require closer monitoring and dose adjustments of the anticoagulant when nandrolone is added or discontinued. Coagulation parameters (e.g. prothrombin time/INR) should be checked frequently, as nandrolone has been reported to prolong prothrombin time in some cases.^[1]^[5]

Hormonal agents: Drugs that affect androgen signaling may theoretically influence the activity of nandrolone. For instance, concurrent use of 5α-reductase inhibitors (like finasteride or dutasteride, used for prostate conditions) could alter nandrolone’s metabolism and reduce its conversion to less active metabolites, potentially modifying its androgenic effects. Likewise, the use of other steroid hormones or hormone-modulating supplements can have unanticipated additive or opposing effects; an example is saw palmetto (Serenoa repens), an herbal product with anti-androgenic properties, which might counteract some actions of anabolic steroids if taken together.^[1]^[5]

Adrenal steroids: Concomitant administration of corticosteroids or ACTH with nandrolone may increase the risk of edema and fluid retention. This is particularly important in patients with cardiac, renal, or hepatic disease, as combined glucocorticoid and androgen therapy can synergistically promote sodium retention and swelling in these vulnerable individuals.^[1]^[5]

Diabetes medications: Anabolic steroids can affect carbohydrate metabolism. Nandrolone may influence blood glucose levels by improving insulin sensitivity in some hypogonadal individuals or, conversely, by reducing glucose tolerance in others. Diabetic patients starting nandrolone should be observed for changes in glycemic control, as adjustments in anti-diabetic medication dosing could be required.^[1]^[5]

Thyroid function tests: Nandrolone decanoate can decrease the levels of thyroxine-binding globulin (TBG) in the bloodstream, leading to a reduction in total T₄ (thyroxine) levels and an increase in resin uptake of T₃/T₄ on assays. Importantly, free thyroid hormone levels and clinical thyroid status remain unchanged; in other words, nandrolone may alter laboratory values without causing true hypothyroidism. Clinicians interpreting thyroid labs in patients on anabolic steroids should be aware of this artifact.^[1]^[5]

In summary, patients should inform their healthcare provider of all concomitant medications, including over-the-counter drugs and supplements, before starting nandrolone decanoate. This helps to avoid and manage potential drug interactions. Regular monitoring of blood work is also advisable to detect changes in lipid profile, liver enzymes, blood count, or other parameters during therapy (since androgens can impact these values).^[1]^[5]

Like all anabolic steroids, nandrolone decanoate is associated with a broad range of potential adverse effects involving multiple organ systems. The occurrence and severity of side effects depend on the dose, duration of use, and patient-specific factors (such as sex and age).^[1]^[6]

Endocrine and Reproductive: In men, nandrolone may suppress the normal hypothalamic-pituitary-gonadal axis, leading to inhibition of testicular function with resultant testicular atrophy and reduced sperm count (oligospermia). Decreased endogenous testosterone production can cause infertility while on therapy, which in most cases may be reversible after discontinuation over time. Male patients may also experience gynecomastia (benign breast tissue enlargement) due to steroid-induced hormonal imbalances. Prolonged or high-dose use in men may carry a risk of chronic priapism (prolonged erections), impotence/erectile dysfunction, and epididymal inflammation.^[1]^[6]

In women, even at therapeutic doses, the most common adverse effect is virilization – the development of male secondary sexual characteristics. Signs of virilization in female patients can include acne, hirsutism (excessive body and facial hair growth), male-pattern baldness, deepening of the voice, increased libido, menstrual irregularities (oligomenorrhea or amenorrhea), and clitoromegaly (enlargement of the clitoris). Many of these masculinizing changes, especially voice deepening and clitoral enlargement, may be irreversible or only partially reversible upon discontinuing the drug. Therefore, female patients require careful monitoring, and if virilization signs emerge, therapy is usually halted promptly to limit permanency.^[1]^[6]

In both sexes, anabolic steroids can cause either an increase or decrease in libido, and mood changes related to hormonal effects are not uncommon.^[1]^[6]

Dermatologic: Androgenic stimulation can lead to sebaceous gland hypertrophy and acne, particularly in women and adolescent males. Oily skin and hair, and predisposition to male-pattern hair loss (alopecia) in those genetically susceptible, have been reported.^[1]^[6]

Psychiatric/CNS: Nandrolone and other AAS may affect mood and behavior. Some individuals experience mood swings, including irritability, aggression, or depression. Patients might report insomnia or changes in mental focus as well. There is a potential for habituation or psychological dependence with anabolic steroids, especially when misused at high doses, leading to withdrawal symptoms upon cessation.^[1]^[6]

Cardiovascular and Metabolic: Nandrolone decanoate may cause fluid retention and edema due to its effects on electrolyte balance (promoting sodium and water retention). This can manifest as swelling in the extremities and, in predisposed individuals, may contribute to or worsen hypertension. Anabolic steroid use has been linked to adverse lipid changes: nandrolone may increase LDL cholesterol and decrease HDL cholesterol levels, potentially accelerating atherogenic risk.^[1]^[6]

Prolonged use or abuse of AAS, even in the absence of other risk factors, has been associated with cardiovascular complications including cardiomyopathy, arrhythmias, and heart failure. Indeed, cases of congestive heart failure and dilated cardiomyopathy have been reported in patients with a history of high-dose steroid abuse, though such severe outcomes are typically seen with supra-physiologic dosages. Even at therapeutic doses, caution is warranted in those with underlying heart disease, and any signs of dyspnea, edema, or chest pain should prompt evaluation.^[1]^[6]

Hematologic: By stimulating erythropoiesis, nandrolone can increase red blood cell mass; in some patients this may lead to polycythemia (elevated hematocrit) which can increase blood viscosity and risk of thrombosis if not monitored. Paradoxically, in patients on anticoagulants, the enhanced clotting factor suppression by androgens can increase bleeding tendency (as noted in Interactions).^[1]^[6]

Hepatic: Unlike oral 17α-alkylated anabolic steroids, nandrolone (being parenteral and not 17α-alkylated) is not commonly associated with acute liver toxicity such as cholestatic jaundice at normal doses. However, serious hepatic adverse effects have been documented with long-term anabolic steroid therapy. Peliosis hepatis – a condition where blood-filled cysts form in the liver – has been reported in patients receiving chronic androgenic steroid treatment. These cysts may be asymptomatic until they cause liver dysfunction or rupture; they have occasionally led to life-threatening intra-abdominal hemorrhage.^[1]^[6]

Hepatocellular neoplasms (liver tumors) have also been observed with extended anabolic steroid use; many are benign adenomas that may regress after drug withdrawal, but malignant liver tumors have been reported in rare cases. Regular monitoring of liver function tests is advised during prolonged therapy.^[1]^[6]

Musculoskeletal: In pediatric patients, anabolic steroids can accelerate epiphyseal closure in the long bones, leading to premature cessation of growth. This effect can result in a permanently reduced adult stature if not detected early; thus, any use of nandrolone in children requires periodic X-ray monitoring of bone age. In adults, supraphysiologic doses of AAS have been linked to tendon injuries, possibly due to disproportionate muscle strength gains outpacing tendon adaptation.^[1]^[6]

Other effects: Nandrolone can cause voice changes (deepening) in women, which may be irreversible. Some users report headaches, nausea, or gastrointestinal discomfort such as diarrhea with anabolic therapy. Changes in glucose tolerance or even mild insulin resistance have been noted in some individuals. Injection-site reactions (pain, redness, or swelling) can occur, though injection-site abscesses are rare when proper technique is used. Because nandrolone decanoate is typically administered in a sesame oil vehicle, allergic reactions are uncommon but possible in those with sesame oil sensitivity.^[1]^[6]

Overall, the safety profile of nandrolone decanoate requires vigilant monitoring. Many side effects are dose-dependent and may be mitigated by using the lowest effective dose for the shortest necessary duration. Some adverse effects (like lipid changes or mild hepatic enzyme elevations) are reversible upon discontinuation, whereas others (virilization, growth stunting, etc.) can leave lasting effects. Patients should be educated on recognizing early signs of serious side effects (such as excessive virilization, jaundice, or edema) and advised to report them promptly. Healthcare providers will periodically evaluate blood counts, liver enzymes, lipid panels, and hormonal levels during therapy to ensure patient safety. By closely supervising therapy and individualizing dosing, practitioners aim to harness the anabolic benefits of nandrolone decanoate while minimizing its risks.^[1]^[6]

Pregnancy: Nandrolone decanoate is contraindicated for use during pregnancy (FDA Pregnancy Category X). Anabolic steroids can cause severe adverse effects on the fetus. In particular, exposure to nandrolone or other androgens in utero, especially during the first trimester, may lead to virilization of a female fetus – for example, development of male-like genitalia in a genetically female fetus. There are no controlled studies of nandrolone in pregnant women because it would be unethical to expose a fetus to this drug; however, animal studies and the pharmacology of the drug strongly indicate risk of teratogenicity and fetal harm.^[1]^[4]

Women who are pregnant or who may become pregnant must not use nandrolone decanoate. If a patient becomes pregnant while receiving nandrolone, the medication should be discontinued immediately and the patient apprised of the potential hazard to the fetus.^[1]^[4]

Lactation: It is unknown whether nandrolone or its metabolites are excreted into human breast milk. Given that many drugs are excreted in breast milk and that anabolic steroids could potentially cause serious adverse effects in a nursing infant, women who are breastfeeding are generally advised not to use nandrolone decanoate.^[1]^[4]

If an anabolic steroid is absolutely indicated in a postpartum patient, a decision should be made to discontinue nursing or avoid the drug altogether, weighing the importance of treatment to the mother. In practice, because nandrolone is usually an elective therapy (for conditions that have alternative treatments or can be deferred), lactating patients are counseled to use other options or to postpone nandrolone until breastfeeding has ceased. Additionally, anabolic steroids may suppress lactation or alter the composition of breast milk due to their hormonal effects, which provides further rationale to avoid these agents during nursing.^[1]^[4]

Contraception: Women of childbearing potential on nandrolone should use effective contraception to prevent pregnancy during therapy.^[1]^[4]

Fertility considerations: Although not directly a pregnancy or lactation issue, it is worth noting that nandrolone can impair fertility in male patients by inducing reversible oligospermia or azoospermia with prolonged use. Men desiring to father a child should be aware that anabolic steroid use may need to be halted well in advance of attempting conception to allow recovery of sperm production.^[1]^[4]

In summary, nandrolone decanoate should not be used in pregnancy or while breastfeeding. Any woman who becomes pregnant while on nandrolone must discontinue it, and nursing mothers are advised to avoid this medication to protect the infant.^[1]^[4]

Proper storage and handling of nandrolone decanoate injection are important to maintain its stability and sterility. The multi-dose vials should be stored at controlled room temperature, typically around 20°–25°C (68°–77°F). Excursions outside this range should be minimized; the compound should not be frozen, and it is best kept in a cool, dry place. The vials must be protected from light. Nandrolone decanoate solution is light-sensitive, and exposure to direct light could potentially degrade the active ingredient over time. For this reason, the medication is often dispensed in amber-colored vials or kept within its carton until ready for use. Users should keep the vial in its original packaging when not in use and store it away from sunlight or strong artificial light.^[1]^[2]

Because this is a compounded sterile preparation, it will have a beyond-use date (BUD) assigned by the pharmacy rather than a manufacturer’s expiration date. The BUD indicates how long the vial’s contents remain stable and sterile under recommended storage conditions. Patients should note the BUD on the label and not use the medication beyond that date. Once the BUD or expiration is reached, any unused solution should be disposed of properly.

The vial should be stored out of reach of children and pets for safety. When handling the vial, users should inspect it for any cracks or damage before each use, as compromised vials could lead to contamination. Syringes and needles used to withdraw and inject the solution should be sterile and preferably used only once (needles should never be re-entered into the vial with a non-sterile needle). If multiple doses are drawn from the same vial over time, the rubber stopper should be swabbed with an appropriate antiseptic (e.g. isopropyl alcohol) before each puncture to maintain sterility.

If the solution appears cloudy, has precipitated (crystals), or shows particles, do not use it and contact the pharmacy. Nandrolone decanoate in solution is usually a clear to yellowish oily liquid; any marked change in appearance could indicate contamination or instability. Likewise, if a vial develops an unusual odor or if there is any suspicion it may have been contaminated or stored improperly, it should be discarded according to medical waste protocols.

Disposal of unused or expired anabolic steroid medication should follow state and federal guidelines for controlled substances. Patients should not simply throw vials in the trash or flush them. Instead, return programs or consultation with the pharmacy for safe disposal methods are recommended due to the medication’s hormonal activity and controlled status.

In summary, store nandrolone decanoate vials at room temperature in a light-protected environment, observe the beyond-use date, and handle the vial with sterile technique. By adhering to these storage and handling recommendations, the potency and sterility of the medication are maintained for the duration of its use.