Can Testosterone Cause Fatty Liver?

Can testosterone cause fatty liver? This is an important question for anyone considering or currently using testosterone therapy. The relationship between testosterone and liver health is complex: the risk depends heavily on the type of preparation used, the dose, and individual health factors. Oral 17-alpha alkylated formulations carry the greatest hepatic risk, while modern transdermal and injectable options used in UK clinical practice have a considerably more favourable safety profile. Understanding the evidence helps patients and clinicians make informed, safe decisions about testosterone replacement therapy.

Can testosterone cause fatty liver disease?

Testosterone can contribute to liver stress, especially with oral 17-alpha alkylated preparations or supraphysiological doses, but modern injectable and transdermal formulations have a substantially lower hepatic risk. Low testosterone may actually be associated with increased fatty liver risk in hypogonadal men.

Testosterone therapy can contribute to liver stress in certain circumstances, but the risk varies considerably depending on the route of administration and the dose used. The liver is responsible for metabolising many hormones and drugs, and when testosterone is taken orally it undergoes extensive first-pass metabolism that can place significant strain on hepatic tissue.

The greatest hepatic risk is associated with oral 17-alpha alkylated testosterone preparations and with supraphysiological doses used in non-medical or performance-enhancing contexts. These preparations are now rarely used in clinical practice in the UK. In individuals using such preparations, first-pass metabolism can lead to elevated liver enzymes, cholestasis, or, in rare cases, more serious conditions including peliosis hepatis (blood-filled cysts in the liver). Hepatocellular carcinoma has been reported in association with long-term, high-dose 17-alpha alkylated androgen use, though this is distinct from the risk profile of modern physiological testosterone replacement therapy (TRT).^[12]

Injectable and transdermal (gel or patch) formulations bypass first-pass hepatic metabolism and are therefore associated with a substantially lower risk of direct liver damage.^[1][6] The MHRA-authorised testosterone products most commonly prescribed in the UK today, such as testosterone gels (for example Testogel and Tostran) and intramuscular injections (for example Nebido), have a considerably more favourable hepatic safety profile. Buccal testosterone preparations have also been used to avoid first-pass metabolism, though their availability in the UK should be confirmed with your prescriber or pharmacist.

The relationship between testosterone and fatty liver disease (medically termed metabolic dysfunction-associated steatotic liver disease, or MASLD, though NHS resources may still use the older term non-alcoholic fatty liver disease, NAFLD) is more nuanced. Low testosterone levels in men have been linked to an increased risk of fatty liver and metabolic syndrome.^[9][13] Some observational research suggests that restoring testosterone to normal physiological levels may improve insulin sensitivity and reduce hepatic fat accumulation in hypogonadal men, though evidence from randomised controlled trials is mixed and this should not be taken as established.^[10][13] Supraphysiological doses, such as those used in non-medical contexts, may have the opposite effect. The evidence base continues to evolve, and individuals should discuss their personal risk with a qualified clinician before starting or continuing testosterone therapy.

Who is most at risk of liver problems from testosterone therapy?

Those using oral 17-alpha alkylated preparations, supraphysiological doses, or who have pre-existing liver disease, obesity, type 2 diabetes, or heavy alcohol use face the greatest risk of testosterone-related liver harm.

People who use oral 17-alpha alkylated testosterone preparations, or who take supraphysiological doses for non-medical purposes, face the greatest risk of testosterone-related liver harm. Beyond formulation and dose, several individual factors can amplify hepatic vulnerability and should be carefully considered before testosterone therapy is initiated or continued.

Those with pre-existing liver conditions, including MASLD (also referred to as NAFLD in some NHS resources), alcoholic liver disease, viral hepatitis, or cirrhosis, are at heightened risk because their liver's capacity to process additional metabolic load is already compromised. Similarly, individuals with obesity, type 2 diabetes, or metabolic syndrome may have underlying hepatic inflammation that makes them more susceptible to further liver stress.

Alcohol consumption is a significant compounding factor. The UK Chief Medical Officers advise keeping alcohol consumption to no more than 14 units per week, spread across several days, to minimise health risks.^[4][5] Regular or heavy alcohol use alongside testosterone therapy increases the burden on the liver and may accelerate the progression of any existing hepatic pathology.

Taking other medicines that are themselves hepatotoxic at the same time as testosterone therapy may increase overall liver risk through additive effects rather than a direct interaction with testosterone itself. Examples of medicines with recognised hepatotoxic potential include certain azole antifungals and diclofenac; before starting testosterone therapy, your prescriber or pharmacist should review all your current medicines using the BNF or relevant SmPCs to identify any that carry hepatotoxic risk. Do not stop or change any prescribed medicine without first speaking to your prescriber.

Age and genetic factors also play a role. Older individuals may have reduced hepatic reserve, and some people carry genetic variants that affect how efficiently the liver processes hormones and drugs. Men who use anabolic-androgenic steroids (AAS) recreationally, often at doses far exceeding therapeutic ranges, represent a particularly high-risk group, with case reports documenting serious liver injury including cholestatic jaundice and liver failure in this population. Anyone in these higher-risk categories should undergo thorough clinical assessment, including baseline liver function tests, before testosterone therapy begins. UK guidance from the British Society for Sexual Medicine (BSSM) and NICE CKS on male hypogonadism provides a framework for pre-treatment assessment and monitoring.

What are the signs of liver damage you should not ignore?

Jaundice, dark urine, pale stools, upper right abdominal pain, and unexplained fatigue are key warning signs of liver damage that require prompt medical attention during testosterone therapy.

Yellowing of the skin or whites of the eyes (jaundice) is one of the most recognisable signs of significant liver dysfunction and should prompt urgent medical attention. Jaundice occurs when bilirubin, a breakdown product of red blood cells normally processed by the liver, accumulates in the bloodstream. Its presence alongside testosterone use warrants urgent clinical review.

Other warning signs that should not be dismissed include:

• Dark urine (described as tea or cola coloured), which can indicate elevated bilirubin excretion through the kidneys

• Pale or clay-coloured stools, suggesting reduced bile flow from the liver into the digestive tract

• Persistent nausea, vomiting or loss of appetite, particularly if these symptoms are new or worsening

• Upper right abdominal pain or tenderness, which may reflect liver enlargement or inflammation

• Unexplained fatigue or weakness that is disproportionate to activity levels

• Swelling of the abdomen (ascites) or legs, which can indicate advanced liver disease affecting fluid regulation

• Easy bruising or prolonged bleeding, as the liver produces clotting factors

It is worth noting that early liver damage is frequently asymptomatic, which is why routine monitoring through blood tests is essential rather than relying on symptoms alone. If you are taking testosterone therapy and develop any of the symptoms listed above, contact your GP promptly. If you are unsure whether your symptoms need urgent attention, call NHS 111 for advice. Do not wait for a routine appointment if symptoms are severe or rapidly worsening. If you experience sudden confusion, extreme drowsiness, or significant abdominal swelling alongside jaundice, seek emergency care via 999 or attend your nearest accident and emergency department, as these may indicate acute liver failure.

If you suspect that testosterone therapy or any other medicine has caused a side effect, you can report this to the MHRA via the Yellow Card Scheme at yellowcard.mhra.gov.uk.

How do doctors monitor liver health during testosterone treatment?

Doctors use periodic liver function tests (LFTs), including ALT, AST, ALP, GGT, bilirubin, and albumin, with baseline testing before treatment and follow-up at three to six months initially, then annually once stable.

Doctors monitor liver health during testosterone treatment primarily through periodic liver function tests (LFTs), which measure enzymes and proteins that reflect hepatic activity and integrity. Standard LFTs include alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), bilirubin, and albumin. Elevated transaminases (ALT and AST in particular) are often the earliest biochemical indicator of hepatocellular stress.

In UK clinical practice, guidance from the BSSM and NICE CKS on male hypogonadism recommends that men receiving testosterone replacement therapy have baseline blood tests before treatment begins, with follow-up testing at intervals determined by the prescribing clinician, typically at three to six months initially and then annually once stable. The frequency may be increased if there are pre-existing risk factors or if early abnormalities are detected. Haematocrit (red blood cell concentration) is also monitored during TRT, as testosterone can stimulate red blood cell production, increasing blood viscosity; the primary concern here is an increased risk of thrombosis and cardiovascular events rather than direct liver strain.^[7][1]

For individuals using injectable testosterone, timing of blood tests relative to the injection cycle matters, as hormone levels fluctuate. Clinicians will usually specify when in the cycle samples should be taken to ensure results are comparable over time, in line with the relevant product SmPC. If LFTs show persistent or significant elevation, the prescribing clinician may reduce the dose, switch to a different formulation, or temporarily suspend treatment while investigating the cause. British Society of Gastroenterology guidance on abnormal liver blood tests provides a framework for when repeat testing, imaging, or hepatology referral is appropriate.^[8]

Imaging, such as liver ultrasound, may be arranged if blood tests suggest structural changes or if there is clinical concern about fatty infiltration or other hepatic pathology. Patients should always inform their prescriber of any new medications, supplements (including herbal products), or changes in alcohol intake, as these can all influence liver function results and overall hepatic health.

Are there safer options if you have an existing liver condition?

Transdermal gels and patches are generally the safest options for those with pre-existing liver conditions, as they bypass first-pass hepatic metabolism; injectable testosterone is also widely used and avoids this risk.

Transdermal testosterone formulations, such as gels and patches, are generally considered the safest options for individuals with pre-existing liver conditions because they avoid first-pass hepatic metabolism entirely. When testosterone is absorbed through the skin, it enters the systemic circulation directly, bypassing the liver's initial processing step and substantially reducing the hepatic burden compared with oral preparations. Injectable testosterone also avoids first-pass metabolism and is widely used in UK clinical practice. The SmPCs for individual products (such as Testogel, Tostran, and Nebido) include specific cautions relating to hepatic impairment and should be reviewed by the prescribing clinician.

For men with significant liver disease, the decision to initiate or continue testosterone therapy requires careful specialist input. A hepatologist and an endocrinologist may need to collaborate to weigh the potential benefits of correcting hypogonadism against the risks of further hepatic stress. In some cases, treating the underlying liver condition first, for example through weight management, alcohol cessation, or antiviral therapy for hepatitis, may improve both liver health and testosterone levels without the need for exogenous hormone therapy.

Lifestyle interventions remain central to managing both low testosterone and fatty liver disease. Weight loss, regular physical activity, reduced alcohol consumption, and a balanced diet can improve insulin sensitivity, reduce hepatic fat, and support endogenous testosterone production. These measures are recommended by NICE (NG49: Non-alcoholic fatty liver disease: assessment and management) as first-line management for MASLD and metabolic syndrome, and they complement any pharmacological approach. The NHS NAFLD/MASLD patient information pages and British Liver Trust resources provide accessible guidance on lifestyle changes and when to seek further help.

Anyone with a known liver condition should ensure their prescriber has full details of their medical history, current medications, and any supplements before any hormonal treatment is started or adjusted. It is important to obtain testosterone therapy only through a registered prescriber and pharmacy; purchasing hormones online from unregistered sources carries serious safety risks, including unknown product quality and no clinical oversight. Contact your GP in the first instance to discuss referral or review. For those exploring medically supervised testosterone therapy or weight-management support, Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online consultations with prescriber review and pharmacist support, where clinically appropriate options may be considered.

Scientific References

1. Testosterone Enantate 250 mg/ml Solution for Injection – Summary of Product Characteristics.
2. NG49: Non-alcoholic fatty liver disease (NAFLD) – assessment and management.
3. Non-alcoholic fatty liver disease (NAFLD).
4. Alcohol consumption: advice on low risk drinking.
5. Drink less alcohol – Better Health.
6. Testosterone – Drugs – BNF.
7. PRAC review does not confirm increase in heart problems with testosterone medicines.
8. Guidelines on the management of abnormal liver blood tests (Newsome PN et al., British Society of Gastroenterology, 2018).
9. Noninvasive Indices of MASLD Are Associated With Hypogonadism in Patients With T2DM (Caretta N et al., 2024).
10. Male hypogonadism: pathogenesis, diagnosis, and management (De Silva NL et al., 2024).
11. Drug-related hepatotoxicity (Navarro VJ, Senior JR, 2006).
12. Multiple hepatic adenomas after long-term therapy with testosterone enanthate – review of the literature (1986).
13. The Effects of Testosterone Replacement Therapy in Adult Men With Metabolic Dysfunction-Associated Steatotic Liver Disease: A Systematic Review and Meta-analysis (2024).
14. Current Update on Nomenclature, Diagnosis, and Management of Metabolic Dysfunction-associated Steatotic Liver Disease: Radiologists' Perspective (2025).

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