Testosterone undecanoate (oral)
Andriol, Jatenzo, Tlando, Kyzatrex, Andriol Testocaps, Oral testosterone undecanoate
Forms: Andriol (Testocaps) is sold in many countries; Jatenzo, Tlando and Kyzatrex are newer US capsules. Injectable undecanoate and other forms have their own cards.
Other esters and forms: Testosterone enanthate, Sustanon (testosterone ester blend), Testosterone cypionate, Testosterone decanoate, Testosterone gel, patch, nasal gel, implant, Testosterone isocaproate, Testosterone phenylpropionate, Testosterone propionate, Testosterone suspension (no ester), Testosterone undecanoate (injection)
Oral steroidsControlled substanceWADA S1.1 · prohibitedEvidence: approved medicine
Testosterone undecanoate in capsules, absorbed together with dietary fat. Not 17α-alkylated: it is not known to cause the liver injury of alkylated oral steroids, but absorption varies.
Legal status: Prescription medicine for hypogonadism; controlled as an anabolic steroid in many countries (US Schedule III); rules vary 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
Medically used for confirmed male hypogonadism by men who prefer capsules to injections or gels; the aim is normal levels. The capsules are designed for replacement levels, not the high levels typical of steroid use in sport.
What people seek and what studies show
It is testosterone itself, so effects follow the blood level reached. Absorption depends on fat in food: without food, levels stayed very low in one study. Newer capsules restored normal levels in most hypogonadal men. There are no studies in athletes; the capsules aim at normal levels, not the high levels used in sport.
Effects
Evidence: Approved medicine — studied in people for its medical use
Sought effects by goal (as reported)
Mass
Sought for: muscle growth, strength, recovery
Cutting
Sought for: keeping muscle in a deficit
Recomposition
Sought for: muscle growth, keeping muscle in a deficit
Strength
Sought for: strength, recovery, muscle growth
Endurance
Sought for: recovery
Works against it: fast heart rate / arrhythmia
Recovery & healing
Sought for: recovery
Health
Sought for: well-being & libido
Works against it: worse cholesterol (HDL↓ LDL↑), higher blood pressure
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.
17 possible side effects
level · how often it is reportedElevated
Suppression of natural testosterone & fertility
commonSuppresses natural testosterone and sperm output. Testosterone usually recovers within months and sperm within about a year; 1 in 10 still had low testosterone at one year, more after long use.
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
Thick blood (hematocrit) / clot risk
commonRaises red cells: in a trial of oral undecanoate hematocrit rose about 3 points, and pressure rose most in men with the largest rise. Sauna or weight-cut dehydration raises it further.
How to notice: Often silent; sometimes headaches, flushed face, itch after a hot shower.
Elevated
Heart strain / heart-muscle thickening
rareHeart-wall thickening and weaker pumping are documented with high-dose steroid use; at replacement levels the TRAVERSE trial found no rise in heart attacks or strokes.
How to notice: Shortness of breath on effort, endurance falling for no training reason, palpitations.
Moderate
Higher blood pressure
commonUS labels warn that it raises blood pressure: about 5/2.5 mmHg on 24-hour monitoring with Jatenzo, more in men treated for hypertension (a boxed warning until 2025).
How to notice: Often silent; sometimes headaches, flushing, nosebleeds — a home monitor shows it. Heavy lifts briefly spike it even in healthy lifters.
Moderate
Worse cholesterol (HDL↓ LDL↑)
commonLowers HDL and raises LDL and ApoB, more at higher doses and in stacks; values usually return to baseline within months of stopping. The changes are silent — only a lipid panel shows them.
How to notice: No symptoms — only visible on a lipid panel.
Moderate
High estrogen (water, gyno risk)
possiblePart converts to estradiol, more at higher doses and higher body fat. Nipple tenderness and water retention are typical signs; a sensitive estradiol test confirms it.
How to notice: Puffiness, sensitive or itchy nipples, mood swings, water weight.
Moderate
Gynecomastia
possiblePossible when estradiol rises. Early tenderness can settle, but established gland tissue usually needs surgery; early changes deserve a doctor's look.
How to notice: A tender lump or swelling under the nipple.
Moderate
Fast heart rate / arrhythmia
possibleIn the TRAVERSE trial even replacement doses slightly raised atrial fibrillation. Palpitations, fainting or chest pain during training need an ECG.
How to notice: Racing heart or skipped beats at rest or in training, shaky hands.
Moderate
Androgenic hair loss
possibleConverted to DHT in skin, it can speed up hair loss in men with a genetic tendency; lost hair may not grow back.
How to notice: More hair in the shower, thinning at the temples or crown.
Moderate
Prostate growth / PSA rise
possibleDHT stimulates prostate growth and can raise PSA; most relevant after 40 or with urinary symptoms. A PSA test tracks it.
How to notice: More frequent urination or a weak stream, especially at night.
Moderate
Irritability, aggression, mood swings
possibleIn a placebo-controlled trial of a high dose most men changed little, but about 1 in 6 became hypomanic, mostly mildly. Irritability that others notice is a warning sign.
How to notice: Short temper, irritability, conflicts with others.
Moderate
Low mood, depression, lethargy
possibleAfter stopping, while natural testosterone recovers, low libido, fatigue and low mood are possible; a doctor can help.
How to notice: Flat mood, low motivation, tiredness; can follow stopping androgens. Overtraining or RED-S can look the same.
Moderate
Black-market quality risk (fakes, contamination)
possiblePharmacy capsules have known content; capsules from unofficial sources may be fake or contain something else.
How to notice: Unexpected effects, pain or infection, a stronger or weaker effect than expected.
MenLow
WomenHigh
Virilization in women (often irreversible)
commonIn women: deeper voice, facial and body hair, clitoral enlargement and menstrual changes; voice and clitoral changes are often permanent.
How to notice: Hoarse or deeper voice, new facial or body hair, menstrual changes, clitoral enlargement.
Low
Water retention / bloating
possibleMild fluid retention is possible, from estrogen and sodium retention; it can push blood pressure up.
How to notice: Puffy face and ankles, softer look, quick weight jumps.
Low
Acne, oily skin
possibleAcne and oily skin are possible; severe or scarring acne needs a dermatologist.
How to notice: Oily skin, spots on back, shoulders and face.
Low
Nausea, GI upset, pancreatitis risk
possibleStomach and bowel side effects have been reported with oral undecanoate capsules.
How to notice: Nausea, fullness, constipation or diarrhea; often worse in hard or long sessions.
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 17 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 (7)
- 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.
ElevatedThick 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.
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.
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 (18)
- 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.
- Taurine — Meta-analysis of 20 small trials: about 4 mmHg lower systolic pressure on average.
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.
ModerateHigh estrogen (water, gyno risk)
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.
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.
ModerateFast heart rate / arrhythmia
Limit caffeine, pre-workouts and other stimulants; with palpitations, stop the suspected drug, pause hard training and get an ECG. Don’t add potassium on your own (supplements, Asparkam/Panangin, salt substitutes): it is dangerous with spironolactone, ARBs/ACE inhibitors or kidney problems; a blood test shows the level.
Measure
How each option helps (1)
- Heart screening: ECG and echocardiogram — An ECG read by athlete criteria separates normal training changes from arrhythmias, conduction or QT problems — key with stimulants, clenbuterol, thyroid hormone or diuretics.
ModerateAndrogenic 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.
ModerateProstate growth / PSA rise
PSA as a baseline, especially after 40; a urologist if urination changes.
Measure
How each option helps (1)
- Regular blood tests — PSA tracks prostate changes on androgens — most relevant after 40 or with urinary symptoms.
ModerateIrritability, aggression, mood swings
Good sleep, fewer stressors, tell someone close what to watch for. About one in three androgen users becomes dependent; if you cannot stop or never feel big enough, talk to a doctor or psychologist.
Measure
How each option helps (2)
- Avoiding alcohol and other liver stressors — Alcohol and other drugs on top of steroids explain much of the link between steroid use and violence.
- Sleep hygiene — Enough sleep lowers irritability and improves impulse control.
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.
ModerateBlack-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.
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
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.
Digestion
Smaller meals, enough fluid and fiber, test race-day food in training first; a doctor for severe abdominal pain.
Measure
Supplement or OTC product
How each option helps (2)
- Working with a doctor — Assesses persistent vomiting or severe belly pain (possible pancreatitis or gallstones) and adjusts prescribed GLP-1 treatment when nausea persists.
- Pancreatin + dimeticone (Pankreoflat) — May ease heaviness and gas after meals; can cause nausea or diarrhea. Not for pork or cow's milk protein allergy (anaphylaxis reported) or early acute pancreatitis.
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.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
Electrolytes (potassium, sodium, magnesium)Low sodium after long events mostly comes from drinking far beyond thirst; heavy sweating in the heat also costs sodium.heart rhythm
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, low mood
Estradiol (sensitive assay)high estrogen, gynecomastia
Prolactingynecomastia
PSAprostate
Home blood-pressure logMeasure seated and rested, not within 30 minutes after training, caffeine or smoking — they change the reading.heart, blood pressure
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, heart rhythm
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
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.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
Electrolytes (potassium, sodium, magnesium)Low sodium after long events mostly comes from drinking far beyond thirst; heavy sweating in the heat also costs sodium.heart rhythm
Estradiol (sensitive assay)high estrogen, gynecomastia
Prolactingynecomastia
Home blood-pressure logMeasure seated and rested, not within 30 minutes after training, caffeine or smoking — they change the reading.heart, blood pressure
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.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
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, low mood
Semen analysisnot earlier than 3 months after stopping, then every 3 months until normalnatural testosterone
Every year
with regular or repeated use
PSAprostate
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, heart rhythm
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
Sports physiciancoordinates everything
Cardiologisthematocrit, heart, cholesterol, blood pressure, heart rhythm
Endocrinologistnatural testosterone, high estrogen, gynecomastia
Psychotherapist / psychiatristmood, low mood
Urologistprostate
Dermatologisthair loss
Gynecologistvirilization, natural testosterone (women)
At home
- Home blood pressure: 2–3 times a week in the morning, keep a log
Get medical help at once if
- 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.
- 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.
- Difficulty or pain when urinating, blood in urine; unable to pass urine at all — urgent care.
- Sudden severe headache, vision changes, numbness or weakness on one side, trouble speaking — call your local emergency number.
- Racing or irregular heartbeat that does not settle at rest, dizziness, fainting (especially during exercise), chest pain — call your local emergency number.
- Losing control of anger, thoughts of harming yourself or others — stop and get help today.
- Thoughts of suicide or self-harm — call your local emergency number or a crisis line right now.
- 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
Testosterone virilizes women: deeper voice, facial and body hair, clitoral enlargement and menstrual changes can appear quickly, and voice and clitoral changes are often permanent. No level above the female range is free of this risk.
Myth & fact
Myth
“Every oral steroid is hard on the liver.”
Fact
Classic liver injury comes from 17α-alkylated steroids such as methyltestosterone. Oral undecanoate is not alkylated, and its US label says it is not known to cause that damage.
Combinations
No specific combination notes for this substance yet. The stack check still adds up side effects that several substances share.
Sources
Jatenzo (testosterone undecanoate) capsules — US prescribing information (DailyMed) (opens in a new tab)Bagchus WM et al. Important effect of food on the bioavailability of oral testosterone undecanoate. Pharmacotherapy 2003 (opens in a new tab)White WB et al. Effects of a novel oral testosterone undecanoate on ambulatory blood pressure in hypogonadal men. J Cardiovasc Pharmacol Ther 2021 (opens in a new tab)Lincoff AM et al., N Engl J Med 2023 (TRAVERSE): testosterone replacement — no rise in major cardiac events, more atrial fibrillation (opens in a new tab)
Check how Testosterone undecanoate (oral) combines with your stack
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