Nandrolone undecanoate
Dynabolon, Nandrolone undecylate
Forms: Other nandrolone esters — decanoate (Deca), phenylpropionate (NPP), laurate, hexyloxyphenylpropionate (Anadur) — have their own cards; the hormone is the same.
Other esters and forms: Nandrolone decanoate, Nandrolone hexyloxyphenylpropionate, Nandrolone laurate, Nandrolone phenylpropionate
Injectable steroidsControlled substanceWADA S1.1 · prohibitedEvidence: approved medicine
Nandrolone with a long undecanoate ester, once sold as Dynabolon. Its fatty-acid chain is longer than the decanoate's, and a longer chain usually means slower release from the injection depot.
Legal status: Controlled anabolic steroid (US Schedule III, UK Class C); prescription-only where still marketed; status varies by country.
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Used in sport for muscle mass and strength, like other nandrolone. As Dynabolon it was a medicine in parts of Europe, also used in children; a 2004 Italian trial tested it in older women with obesity.
What people seek and what studies show
Data on this ester are scarce: in older women with obesity on diet and exercise it added nothing to body composition or strength over a few weeks. Nandrolone itself added about 2.6 kg of fat-free mass without fat change in a placebo-controlled trial in experienced bodybuilders. Joint, tendon or cartilage repair is unproven.
Effects
Evidence: Approved medicine — studied in people for its medical use
Sought effects by goal (as reported)
Mass
Sought for: muscle growth, strength, recovery
Recomposition
Sought for: muscle growth
Strength
Sought for: strength, recovery, muscle growth
Works against it: tendon / ligament injury risk
Endurance
Sought for: recovery
Recovery & healing
Sought for: recovery
Possible side effects
Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.
19 possible side effects
level · how often it is reportedElevated
Suppression of natural testosterone & fertility
commonStrongly suppresses LH, FSH, natural testosterone and, with longer use, sperm production; a long ester is expected to delay the start of recovery, which often takes many months.
How to notice: Lower libido and energy, smaller testicles; after stopping — low natural testosterone on tests, often with tiredness and low mood.
In women: Menstrual changes or missed periods, lower libido and energy; reduced fertility.
Elevated
Black-market quality risk (fakes, contamination)
commonPharmaceutical supply is hard to find; most of what circulates is underground, with risks of wrong content, substitution and non-sterile oil.
How to notice: Unexpected effects, pain or infection, a stronger or weaker effect than expected.
Elevated
Heart strain / heart-muscle thickening
possibleNot 'athlete's heart': lifters with years of steroid use pumped weaker than non-using lifters and had more coronary plaque; nandrolone labels warn of edema, sometimes with heart failure.
How to notice: Shortness of breath on effort, endurance falling for no training reason, palpitations.
Moderate
Thick blood (hematocrit) / clot risk
commonUsed medically to raise hemoglobin in kidney anemia; in a healthy athlete it thickens the blood, and dehydration from weight cuts or heat adds to it. A blood count tracks it.
How to notice: Often silent; sometimes headaches, flushed face, itch after a hot shower.
Moderate
Low libido / erectile problems
possibleImpotence and libido changes are listed on nandrolone labels; they are more likely when natural testosterone is suppressed and estrogen or prolactin are off balance.
How to notice: Lower desire, weaker or less frequent erections.
In women: Lower desire and arousal.
Moderate
High prolactin / progestogenic effects
possibleActs on progesterone receptors, and raised prolactin has been reported in users; low libido or nipple discharge are reasons to test prolactin.
How to notice: Lower libido, weaker erections, nipple sensitivity or discharge.
Moderate
Gynecomastia
possibleEstrogen plus progestogenic activity can trigger breast-gland growth; gynecomastia is listed on nandrolone labels. Early tenderness deserves a doctor's look.
How to notice: A tender lump or swelling under the nipple.
Moderate
Worse cholesterol (HDL↓ LDL↑)
possibleIn a controlled trial a moderate dose alone changed lipids little, though even a single dose raised ApoB; higher doses and stacks lower HDL markedly. Only a lipid panel shows it.
How to notice: No symptoms — only visible on a lipid panel.
Moderate
Higher blood pressure
possibleFluid and sodium retention can raise blood pressure, especially in stacks, usually without symptoms; home readings at rest, not right after training, show the trend.
How to notice: Often silent; sometimes headaches, flushing, nosebleeds — a home monitor shows it. Heavy lifts briefly spike it even in healthy lifters.
Moderate
Low mood, depression, lethargy
possibleDepression and insomnia are on nandrolone labels; after stopping, while own testosterone is still suppressed, low mood, fatigue and low libido can follow.
How to notice: Flat mood, low motivation, tiredness; can follow stopping androgens. Overtraining or RED-S can look the same.
Moderate
Tendon / ligament injury risk
possibleClass data: steroid-using bodybuilders had about 9 times more tendon ruptures than non-using lifters, upper-body ones only in users; a quarter followed local pain.
How to notice: Pain at tendon attachments under heavy load; in steroid-using bodybuilders about a quarter of ruptures followed such pain.
Moderate
Kidney strain
rareSteroid-using bodybuilders had more protein in urine, and FSGS is reported. Muscle mass, training and creatine raise creatinine, so cystatin C and a urine test judge kidneys better.
How to notice: Usually silent; foamy urine or swelling in later stages. Big muscle mass or creatine also raise creatinine.
MenLow
WomenHigh
Virilization in women (often irreversible)
commonIn women: voice deepening, facial hair, clitoral enlargement and menstrual changes; nandrolone labels note some changes remain even after prompt stopping.
How to notice: Hoarse or deeper voice, new facial or body hair, menstrual changes, clitoral enlargement.
Low
Too-low estrogen (joints, libido, mood, lipids)
possibleUsed without testosterone, it suppresses natural testosterone while forming little estrogen; low estrogen can bring joint aches, low libido and low mood.
How to notice: Aching, stiff joints, low libido, flat mood, poor sleep.
Low
High estrogen (water, gyno risk)
possibleConverts to estrogen far less than testosterone, yet can still add to water retention and breast tenderness in stacks.
How to notice: Puffiness, sensitive or itchy nipples, mood swings, water weight.
Low
Water retention / bloating
possibleEdema and sodium retention are listed on nandrolone labels; usually mild in healthy people.
How to notice: Puffy face and ankles, softer look, quick weight jumps.
Low
Acne, oily skin
possibleOily skin and acne can occur, though its androgenic effect in skin is weaker than testosterone's.
How to notice: Oily skin, spots on back, shoulders and face.
Low
Androgenic hair loss
possibleIn scalp and skin 5α-reductase turns it into a weaker androgen (DHN), so hair loss is less typical than with testosterone, though possible.
How to notice: More hair in the shower, thinning at the temples or crown.
Low
Injection pain, infection, oil cough
possibleSoreness at the injection site is possible; redness, heat or fever suggest infection and need medical care.
How to notice: Soreness, lumps; a short coughing fit right after an injection.
What the levels mean
Lowbackground — just be aware
Moderatewatch for signs
Elevatedneeds regular control
Highcritical — can be life-threatening or permanent
Level: general category from the literature, not your personal risk
How often
- common
- reported often
- possible
- reported in some people
- rare
- reported occasionally
How to lower the risks
For 16 of 19 possible side effects there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. For the rest — general advice. No measure removes a risk completely. Prescription medicines are listed only for a doctor to decide on, after tests — they have side effects of their own.
ElevatedSuppression of natural testosterone & fertility
Check hormones before and after; if they stay low, see an endocrinologist. Hard training on too little food (RED-S) also lowers testosterone.
Measure
Only if a doctor prescribes
How each option helps (8)
- Regular blood tests — LH, FSH and testosterone show how deep suppression is and whether natural production has recovered afterwards.
- Working with a doctor — Assesses how deep suppression is and guides recovery afterwards, including fertility testing.
- Choriogonadotropin alfa (recombinant hCG) — A doctor may consider it off-label to preserve fertility (it keeps the testes working); it does not restart the pituitary. Risks: higher estradiol, gynecomastia. Has side effects of its own.
- Clomiphene — A doctor may consider it after stopping, guided by hormone tests; most men recover on their own within months, and lasting benefit is unproven. Risks: vision changes, mood swings, rare clots. Has side effects of its own.
- hCG (urinary human chorionic gonadotropin) — A doctor may consider it to preserve fertility (in men it keeps the testes working); it does not restart the pituitary, so natural LH still has to recover. Risks: higher estradiol, gynecomastia. Has side effects of its own.
- Tamoxifen — A doctor may consider it after steroids are stopped, guided by hormone tests; it has not been tested for this after steroid use. Risks: blood clots, vision changes. Has side effects of its own. Not offered to women: in the women’s view it adds to a risk this substance already carries.
- Follicle-stimulating hormone (follitropins, menotropins) — A fertility doctor may consider adding it to hCG when semen tests and FSH stay low; it does not restart the pituitary. Risks: gynecomastia, acne. Has side effects of its own.
- Toremifene — A doctor may consider it after steroids are stopped, guided by hormone tests; it raised testosterone in subfertile men but was never tested after steroids. Risks: QT prolongation, clots. Has side effects of its own. Not offered to women: in the women’s view it adds to a risk this substance already carries.
ElevatedBlack-market quality risk (fakes, contamination)
Products obtained without a prescription are often fake, mislabeled or non-sterile, and there is no way to check at home. For legal supplements, third-party testing (Informed Sport, NSF) lowers, but does not remove, the risk of a positive doping test.
ElevatedHeart strain / heart-muscle thickening
Regular cardio, blood pressure control, an echo as a baseline and then yearly, read by a cardiologist who knows athletes’ hearts.
Measure
Only if a doctor prescribes
How each option helps (9)
- Heart screening: ECG and echocardiogram — Echocardiography shows wall thickening and reduced pumping early, while stopping AAS and treating BP can still help.
- Working with a doctor — Orders ECG and echocardiography and treats early heart changes.
- Home blood-pressure monitoring — Keeping BP controlled is one of the main ways to limit heart-wall thickening.
- Regular cardio training — Supports heart and vessel function, but does not reverse steroid-related heart thickening or weakening.
- ACE inhibitors (ramipril, perindopril, lisinopril) — Standard treatment for heart failure; shrink a thickened heart wall in hypertension. An echo helps tell athlete's heart from hypertensive or steroid thickening; the steroid risk remains. Has side effects of its own.
- Bisoprolol — In heart failure with weak pumping it lowered deaths in trials; doctors add it to standard therapy. Not studied in steroid users; the steroid risk to the heart remains. Has side effects of its own.
- Carvedilol — A doctor may add it when tests show weak heart pumping; in heart failure it lowered deaths. Not studied in steroid users, and it does not undo steroid damage. Has side effects of its own.
- Losartan / valsartan (angiotensin receptor blockers) — Shrink a thickened heart wall in hypertension at least as well as other BP drugs. An echo helps tell athlete's heart from hypertensive or steroid thickening; the steroid risk remains. Has side effects of its own.
- Telmisartan — In high blood pressure, ARBs shrink a thickened heart wall at least as well as other BP drugs. Not studied in steroid users; the steroid risk to the heart remains. Has side effects of its own.
ModerateThick blood (hematocrit) / clot risk
Check the blood count regularly; if hematocrit stays high, a doctor decides — usually stopping or reducing the cause, sometimes therapeutic phlebotomy, never blood-bank donation. Dehydration in long or hot sessions and long flights add to clot risk.
Measure
How each option helps (3)
- Regular blood tests — A blood count shows hematocrit and hemoglobin climbing toward the range where clot and stroke risk rises.
- Therapeutic phlebotomy prescribed by a doctor — Only on a doctor's decision, never at a blood bank. Lowers hematocrit quickly but temporarily; repeated sessions drain iron, and a lower clot risk is unproven.
- Working with a doctor — Manages thick blood by changing what you use or, if justified, by therapeutic phlebotomy; dehydration, long flights and injury immobilization add to clot risk in athletes.
ModerateLow libido / erectile problems
Find the cause by tests (estradiol, prolactin, testosterone) rather than guessing.
Measure
How each option helps (1)
- Working with a doctor — Finds the cause of low libido or erectile problems instead of masking it.
ModerateHigh prolactin / progestogenic effects
Test prolactin if libido drops; a doctor decides on correction.
Measure
How each option helps (1)
- Regular blood tests — Prolactin testing matters with 19-nor compounds and helps explain low libido or nipple discharge.
ModerateGynecomastia
React early: see a doctor at the first lump, check estradiol and prolactin.
Measure
How each option helps (1)
- Working with a doctor — Early assessment of breast-tissue growth allows treatment before the change becomes permanent.
ModerateWorse cholesterol (HDL↓ LDL↑)
Avoid combining several oral steroids; regular cardio, soluble fiber (psyllium), less saturated fat and alcohol; if LDL/ApoB stay high, a doctor may consider a statin. Omega-3 only lowers triglycerides.
Measure
Supplement or OTC product
How each option helps (8)
- Regular blood tests — A lipid panel with ApoB shows how far HDL has dropped and LDL risen — changes you cannot feel.
- Working with a doctor — Interprets lipids and ApoB and decides whether a statin or other therapy is warranted.
- Avoiding alcohol and other liver stressors — Alcohol raises triglycerides; its small HDL bump does not lower heart risk.
- Regular cardio training — Raises HDL a little and lowers triglycerides; it cannot offset a steroid-driven fall in HDL on its own.
- Berberine — Placebo-controlled meta-analysis: LDL about 0.5 and triglycerides about 0.4 mmol/L lower; HDL unchanged. Trials are mostly small; no statin substitute.
- Citrus bergamot — Pooled small trials show lower LDL and triglycerides, but certainty is low to very low; it is no replacement for statins.
- Omega-3 (fish oil, EPA/DHA) — Lowers triglycerides but does not fix the steroid HDL drop, the main lipid harm; omega-3 supplements may even raise LDL (IOC).
- Psyllium husk fiber — Lowers LDL by about 0.2–0.3 mmol/L (roughly 5–10%), also on top of doctor-prescribed statins; no effect on HDL.
ModerateHigher blood pressure
Less salt, regular cardio, good sleep, home readings; if it stays high — a doctor, and a talk about maximal lifts.
Measure
Supplement or OTC product
How each option helps (19)
- Home blood-pressure monitoring — Persistently high resting readings mean seeing a doctor. For athletes, guidance prefers ARBs or ACE inhibitors, which don't limit exercise capacity; diuretics are banned in sport.
- Regular cardio training — In a meta-analysis of trials, endurance training lowered resting BP by about 8/5 mmHg in people with high BP and only slightly in those with normal BP.
- Working with a doctor — Diagnoses persistent hypertension and prescribes treatment when needed.
- Avoiding alcohol and other liver stressors — Regular drinking raises blood pressure; cutting it out lowers it.
- Coenzyme Q10 — Inconsistent: some analyses show a small systolic drop in cardiometabolic disease, but a Cochrane review found no clinically meaningful effect.
- Magnesium — Meta-analysis of 34 trials in adults, not athletes: about 2 mmHg lower systolic pressure on average.
- Magnesium aspartate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium chloride — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium citrate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium gluconate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium glycinate (bisglycinate) — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium lactate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium malate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium orotate — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium oxide — On average magnesium lowers blood pressure only slightly — not a substitute for a doctor's assessment of high pressure found at a sports check.
- Magnesium taurate — Meta-analysis of trials: about 2 mmHg lower systolic pressure on average — too small to replace a doctor's assessment of high pressure found at a sports check.
- Omega-3 (fish oil, EPA/DHA) — Small drop of a few mmHg, mainly in people with untreated high blood pressure.
- Potassium — Meta-analysis of trials: about 3.5 mmHg lower systolic pressure on average, seen only in people with hypertension.
- Taurine — Meta-analysis of 20 small trials: about 4 mmHg lower systolic pressure on average.
ModerateLow mood, depression, lethargy
Keep routine and social contact; talk to a specialist if low mood persists; a sports physician can check for overtraining and RED-S.
Measure
How each option helps (2)
- Working with a doctor — Mood problems, including the low after stopping steroids, are treatable; a doctor can refer you to mental-health care.
- Sleep hygiene — Good sleep supports mood, especially in the low-hormone phase after stopping steroids.
ModerateTendon / ligament injury risk
Progress weights gradually — strength rises faster than tendons adapt; with persistent tendon pain, cut the load and see a sports physician.
ModerateKidney strain
Drink enough, more in heat; control blood pressure; avoid regular painkillers (NSAIDs) and any during long or hot events; no weight cutting by dehydration.
Measure
How each option helps (3)
- Fluid & electrolyte management — Good hydration eases kidney stress from heavy training and heat; dehydration plus NSAIDs is a classic cause of acute kidney injury.
- Regular blood tests — Creatinine runs high with big muscle mass, creatine and hard training, and standard eGFR formulas mislead in athletes; compare with your own baseline and add cystatin C and urinalysis.
- Working with a doctor — Investigates protein in the urine or falling kidney function and can start treatment that slows kidney damage.
MenLow
WomenHigh
Stop at the first voice change and see a doctor — early stopping matters.
Measure
How each option helps (1)
- Working with a doctor — Steroid labels say to stop at the first mild signs (hoarse voice, facial hair, clitoral growth) to prevent permanent change; checks catch them early but do not make use safe.
Low-level side effects
Low estrogen
Avoid controlling estrogen blindly; adjust only by blood tests with a doctor.
Measure
How each option helps (1)
- Regular blood tests — Testing ends guesswork use of aromatase inhibitors — prescription drugs that can push estrogen too low and harm joints, libido, mood and lipids.
High estrogen
Check estradiol by blood test before acting on symptoms; keep salt and body fat in check.
Measure
How each option helps (2)
- Regular blood tests — A sensitive estradiol test shows whether water retention or nipple tenderness really comes from high estrogen.
- Working with a doctor — Prescription estrogen control is safer when adjusted by lab results than by guesswork.
Water retention
Steady salt and water intake, cardio, check estradiol.
Measure
How each option helps (1)
- Working with a doctor — Tells harmless water retention from swelling due to heart, kidney or liver trouble; steroid labels warn that edema can come with heart failure.
Acne
Gentle skin care, cleansing after training, a dermatologist if it spreads.
Supplement or OTC product
How each option helps (3)
- Adapalene — Reduces spots in many users. Redness, scaling, dryness and stinging are common early and usually ease; acne may look worse at first. Rarely, allergic swelling.
- Benzoyl peroxide — A first-line acne option. Dryness, redness and peeling are common at first; it bleaches hair, towels and training clothes; rarely, serious allergy. Severe steroid acne needs a dermatologist.
- Zinc — Trials show a modest drop in inflamed spots, weaker than antibiotics; steroid acne is driven by androgens.
Hair loss
Ketoconazole shampoo, minoxidil, a dermatologist early if you are prone to it.
Supplement or OTC product
How each option helps (1)
- Minoxidil (topical) — Slows thinning and regrows some hair; scalp itching and early temporary shedding are common, unwanted facial hair possible. Gains fade once stopped.
Injection site
Sterile technique, never share needles, vials or pens; see a doctor for a hot, swollen site. If equipment was ever shared, test for HIV and hepatitis B/C and ask about hepatitis B vaccination.
Check-ups and blood tests
Which tests and check-ups to do and when. This is a guide — agree the exact schedule with a sports physician.
Baseline tests
your own starting values — every later result is compared with them
Lipid panel (HDL, LDL, triglycerides, ApoB)In athletes, a high LDL can also be a sign of too little food for the training (RED-S) — tell the doctor about dieting.low estrogen, cholesterol
Complete blood count (hematocrit, hemoglobin)Endurance training dilutes the blood (“sports anemia”), dehydration concentrates it — test hydrated and rested, against your own baseline.hematocrit
Kidney panel (creatinine, eGFR, cystatin C)Creatinine reads higher with big muscle mass or creatine; cystatin C barely depends on muscle and helps judge the kidneys in athletes.blood pressure, kidneys
Testosterone (total, free), LH, FSH, SHBGTestosterone also falls with hard training on too little food (RED-S) — test in the morning, rested, and tell the doctor about dieting.natural testosterone, libido, low mood
Estradiol (sensitive assay)low estrogen, gynecomastia, libido
Prolactinprolactin, gynecomastia, libido
Home blood-pressure logMeasure seated and rested, not within 30 minutes after training, caffeine or smoking — they change the reading.heart, blood pressure, kidneys
ECGTraining changes the ECG in ways that are normal for athletes; ask for a reading by the international athlete criteria, which separate these from disease.heart
Echocardiogram (heart ultrasound)Weight training alone does not weaken the heart’s pumping or relaxation; in a lifter that is not “athlete’s heart” — in steroid users it was linked to the drugs.heart
UrinalysisHard exercise can briefly put protein and blood into the urine, usually gone within a few days — test after rest and repeat before drawing conclusions.kidneys
While taking
about 4–6 weeks in, then every 6–8 weeks — agree the exact schedule with your doctor
Lipid panel (HDL, LDL, triglycerides, ApoB)In athletes, a high LDL can also be a sign of too little food for the training (RED-S) — tell the doctor about dieting.low estrogen, cholesterol
Complete blood count (hematocrit, hemoglobin)Endurance training dilutes the blood (“sports anemia”), dehydration concentrates it — test hydrated and rested, against your own baseline.hematocrit
Kidney panel (creatinine, eGFR, cystatin C)Creatinine reads higher with big muscle mass or creatine; cystatin C barely depends on muscle and helps judge the kidneys in athletes.blood pressure, kidneys
Estradiol (sensitive assay)low estrogen, gynecomastia, libido
Prolactinprolactin, gynecomastia, libido
Home blood-pressure logMeasure seated and rested, not within 30 minutes after training, caffeine or smoking — they change the reading.heart, blood pressure, kidneys
UrinalysisHard exercise can briefly put protein and blood into the urine, usually gone within a few days — test after rest and repeat before drawing conclusions.kidneys
After stopping
4–8 weeks after stopping (later after long-acting injections), then until values return to baseline
Lipid panel (HDL, LDL, triglycerides, ApoB)In athletes, a high LDL can also be a sign of too little food for the training (RED-S) — tell the doctor about dieting.low estrogen, cholesterol
Complete blood count (hematocrit, hemoglobin)Endurance training dilutes the blood (“sports anemia”), dehydration concentrates it — test hydrated and rested, against your own baseline.hematocrit
Kidney panel (creatinine, eGFR, cystatin C)Creatinine reads higher with big muscle mass or creatine; cystatin C barely depends on muscle and helps judge the kidneys in athletes.blood pressure, kidneys
Testosterone (total, free), LH, FSH, SHBGTestosterone also falls with hard training on too little food (RED-S) — test in the morning, rested, and tell the doctor about dieting.natural testosterone, libido, low mood
Semen analysisnot earlier than 3 months after stopping, then every 3 months until normalnatural testosterone
Every year
with regular or repeated use
ECGTraining changes the ECG in ways that are normal for athletes; ask for a reading by the international athlete criteria, which separate these from disease.heart
Echocardiogram (heart ultrasound)Weight training alone does not weaken the heart’s pumping or relaxation; in a lifter that is not “athlete’s heart” — in steroid users it was linked to the drugs.heart
Which doctors can help
Endocrinologistnatural testosterone, low estrogen, prolactin, gynecomastia, libido
Cardiologistheart, cholesterol, blood pressure, hematocrit
Urologistlibido
Nephrologistkidneys
Psychotherapist / psychiatristlow mood
Sports physiciantendons
Gynecologistvirilization, natural testosterone, libido (women)
At home
- Home blood pressure: 2–3 times a week in the morning, keep a log
Get medical help at once if
- Chest pain or pressure, fainting or near-fainting on exertion, breathlessness on light effort, swollen ankles — stop training and seek urgent care; collapse — call your local emergency number.
- A painful lump under the nipple or nipple discharge — see a doctor early, while it can still regress; a hard, painless or fixed lump, skin dimpling or bloody discharge — see a doctor promptly.
- Sudden severe headache, vision changes, numbness or weakness on one side, trouble speaking — call your local emergency number.
- Swelling, pain or redness in one leg (especially after a long flight) — urgent care; sudden breathlessness, chest pain, one-sided weakness or numbness, trouble speaking or seeing — call your local emergency number.
- Much less urine than usual, cola-colored urine (especially with severe muscle pain after hard training), new swelling, flank pain — see a doctor now.
- Thoughts of suicide or self-harm — call your local emergency number or a crisis line right now.
- A snap and sudden sharp pain in a tendon, inability to load the limb — stop training and get it examined.
- Deepening voice, new facial hair, clitoral enlargement — stop and see a doctor: changes can become permanent. (women)
In an emergency, call your local emergency number.
For women
A long ester is expected to keep effects going long after the last injection. Voice deepening, facial hair and clitoral enlargement can be permanent; nandrolone labels note some changes persist even after prompt stopping.
Myth & fact
Myth
“Nandrolone heals joints and tendons.”
Fact
No human study shows repair of joints, tendons or cartilage, and steroid-using bodybuilders had about nine times more tendon ruptures than non-using lifters, upper-body ones only in users.
Combinations
No specific combination notes for this substance yet. The stack check still adds up side effects that several substances share.
Sources
Sartorio A et al. Body mass reduction in obese females aged 61–75 years: diet and training alone or with rGH or nandrolone undecanoate. Eur J Endocrinol 2004 (opens in a new tab)van der Vies J. Pharmacokinetics of anabolic steroids. Wien Med Wochenschr 1993 (opens in a new tab)DailyMed: nandrolone decanoate injection label (US prescribing information) (opens in a new tab)van Marken Lichtenbelt WD et al., Med Sci Sports Exerc 2004: nandrolone decanoate vs placebo in experienced bodybuilders — fat-free mass gain without fat change (opens in a new tab)Kanayama G et al., Am J Sports Med 2015: tendon ruptures in steroid-using vs non-using bodybuilders (HR ≈ 9; upper-body ruptures only in users) (opens in a new tab)
Check how Nandrolone undecanoate combines with your stack
Possible side effects by body system, combinations, how to lower the risks and which tests to do — free.
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