Testosterone Injections Side Effects Heart

Written by Ben Bunting: BA, PGCert. (Sport & Exercise Nutrition) // British Army Physical Training Instructor // S&C Coach.


Understanding the possible side effects of testosterone injections for cardiovascular health is of utmost importance.

Testosterone replacement therapy (TRT) has become an increasingly popular way of treating low testosterone levels; however, it's important not to overlook possible risks involved in TRT therapy.

TRT may provide many advantages, including increased muscle mass and mood enhancement; however, studies have also identified possible risks - particularly to cardiovascular health - of taking testosterone injections such as testosterone shots to increase risk for heart disease, blood clots and stroke.

Researchers suspect that high testosterone levels could contribute to an increase in red blood cell production, potentially contributing to blood clot formation.

Additionally, testosterone injections have been linked to changes in cholesterol levels; with some studies showing an associated reduction of "good" (HDL) and an increase in "bad" (LDL).

Knowing the potential side effects of testosterone injections is vital when considering hormone replacement therapy (HRT).

Consulting with healthcare providers to evaluate if the benefits outweigh the potential risks is essential to making informed decisions and prioritizing heart health while undertaking hormone replacement therapy.

TRT Injections

Testosterone, the natural anabolic hormone produced in men's testicles and women's ovaries and adrenal glands, is a potency anabolic agent with powerful anabolic effects.

If someone suffers from low levels of the hormone (known as hypogonadism) prescription testosterone replacement therapy can restore healthy production levels and relieve life-disrupting symptoms such as fatigue, loss of muscle mass or erectile dysfunction.

TRT injections are the most popular form of testosterone replacement therapy (TRT), however, there are various delivery mechanisms.

Some patients prefer gels applied directly to their skin twice each day, while other individuals may choose patches for armpits, biceps, or groin application.

Most individuals prefer injections as these directly enter their bloodstream for consistent and highest amounts of pure, crystalline Testosterone delivery to their bodies and consistent results.

Physicians typically prescribe testosterone replacement therapy (TRT), depending on an individual's medical history and current symptoms.

Most often, doctors suggest combining different esters - molecules attached to testosterone that allow timed release - such as propionate, enanthate and cypionate -- in order to achieve the best combination of results.

They will also devise a treatment plan that includes injection frequency/timing as well as additional medications as necessary.

Starting TRT may cause changes to your mood; this is caused by hormones adjusting to new Testosterone levels, and should typically subside with time.

While on TRT, it's essential that baseline bone density testing and regular lab tests be completed.

These should include tests to measure your testosterone, PSA (marker of prostate health and cancer), hematocrit and DXA scan for osteoporosis and CBC to monitor liver enzyme levels.

Long-term TRT treatment was found to raise cholesterol levels, though further investigation needs to be conducted into its impact. Furthermore, testosterone replacement therapy increases the risks of breast and prostate cancer in some men.

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The Importance of Heart Health

The heart is a critical organ, pumping vital nutrient-rich blood through your system to deliver oxygen and remove waste products, providing oxygen while eliminating waste products.

Furthermore, it plays an integral part in keeping you healthy by lowering the risk of stroke, high blood pressure and diabetes.

While genetic causes cannot always be avoided or mitigated, many heart issues can be mitigated or avoided by adopting healthy lifestyle practices such as eating nutritious diets, being physically active regularly, getting ample restful sleep and managing stress effectively.

Some may only pay attention to their heart health once diagnosed with serious heart conditions; however, living a healthier lifestyle should start early on and remain consistent throughout your life.

If you want to prevent heart disease, begin by:

  • Limiting alcohol consumption
  • Eating plenty of fruits and vegetables in your diet
  • Engaging in physical activity
  • Not smoking and avoiding secondhand smoke exposure as much as possible
  • Getting enough restful sleep
  • Managing stress reduction techniques
  • Staying away from sugary drinks
  • Avoiding sodium-rich foods 
  • Eating less saturated and trans-fatty foods

Be sure to visit your doctor regularly for medical checkups.

They can conduct a physical exam, ask about a family history of heart disease and run blood tests that measure cholesterol, blood pressure and other indicators that impact heart health.

Based on your risk profile, your physician may suggest medications to lower or control these factors and decrease their effects.

Care of your heart can have profoundly positive results across your entire body, improving mood, immunity, sleep quality and digestion. A strong heart can contribute to longer and more fulfilling lives.

Healthy diet and lifestyle habits can not only benefit your heart, but can also lower risks associated with arthritis, diabetes, cancer and high blood pressure. Maintaining a strong heart is central to overall wellbeing and immune health.

Testosterone and Cardiovascular Health

Testosterone is the primary male sex hormone, with numerous androgenic effects on male development from embryo to adulthood.

These include virilization in early embryonic development, secondary sexual characteristics (adrenarche) during puberty, increased bone formation, muscle mass increase and spermatogenesis during adulthood.

Most circulating testosterone is bound by sex hormone-binding globulin/albumin for safe storage while the small amount that remains active binds directly to cell receptors or alter gene transcription - 95% of total testosterone comes directly from Leydig cells of testes under control of pituitary gonadotropin/luteinizing hormone.

Although testosterone has long been suspected to cause heart disease, no direct evidence has ever been presented as support.

Studies in animals have suggested that its presence promotes atherosclerosis while some clinical research points towards abuse leading to high blood pressure, heart attacks, and other cardiovascular events.

Furthermore, testosterone may interact with other cardiac risk factors like cholesterol levels, blood sugar, or triglycerides for further increases.

Researchers often ascribe differences in sex hormone levels as the culprit behind gender disparities in cardiovascular disease risk.

But other factors, including age, family history, exercise, smoking cessation, diet and cholesterol/blood pressure medications as well as body weight and personality traits may play a part in these effects. 

The Effects of Hypogonadism on the Heart

Male hypogonadism occurs when the body does not produce enough testosterone, an essential hormone in male growth and development during puberty and in sperm production.

Males experiencing male hypogonadism can experience various signs and symptoms depending on its cause and when it first arises.

Many men with low testosterone levels are at an increased risk for heart disease and stroke, according to research published in 2021.

Testosterone plays an essential role in maintaining muscle mass, bone density and sexual function - as well as being essential for brain development and sexuality.

Low levels have been linked to erectile dysfunction, cardiovascular disease and decreased bone density - among many other problems.

Atherosclerotic cardiovascular disease is a leading cause of morbidity and mortality worldwide and its pathogenesis involves multiple events and risk factors; hypogonadism appears to play an integral part.

Research on testosterone's relation to atherosclerosis remains complex but this paper connects these lines of evidence into an accessible clinical analysis for clinicians. 

Testosterone Effects On The Heart

Testosterone is best known for its role in male sexual development and muscle building.

But testosterone also plays a significant role in cardiovascular health, directly impacting heart cells and circulation.

Lower testosterone levels have been linked with an increased risk of cardiovascular disease such as heart attacks and stroke, but whether low testosterone causes these detrimental impacts has yet to be established.

Kristen Sueoka, MD and colleagues at UCSF recently conducted a groundbreaking study that revealed naturally high testosterone levels were linked with less heart disease among older men than those with low levels.

Their research, presented at an Endocrine Society conference in San Diego in June, tracked nearly 700 older men for four years while surveying their health, symptoms and hospital records for heart attacks, coronary artery surgery or blocked arteries resulting in heart failure due to blocked arteries.

Sueoka's study marked the largest trial to date of testosterone therapy, as well as being the first to measure its long-term effects on heart disease risk factors specifically.

Researchers randomly assigned patients either testosterone or placebo gel on their skin and conducted surveys about health, hospital records, electrocardiograms and electrophysiological tests on them to ascertain if any heart problems had arisen related to taking medication.

Studies have raised concerns regarding the link between heart disease and testosterone, but Sueoka and her team's research is particularly pertinent since erectile dysfunction, the primary complaint among men 40 or over visiting doctors for health issues such as erectile dysfunction, is often due to atherosclerosis in their arteries - which restricts blood flow through them.

The Effect of Steroids on the Heart

Anabolic steroids increase your risk for cardiovascular issues like infarction or stroke through early atherosclerosis, vascular calcification, thrombosis and polycythemia or direct myocardial injury caused by their use.

Researchers found that men who used steroids for two years or more had worse heart function than those who never did, as well as more plaque build-up in their arteries; the longer they used steroids, the greater was their accumulation.

Plaque is one of the key contributors to heart disease; when broken-off pieces get stuck in blood vessels they can block blood flow directly to the heart and lead to a heart attack.

Steroid users also had lower levels of HDL cholesterol - the "good" variety. HDL helps prevent plaque build-up in arteries by keeping levels of this beneficial type high.

Researchers conducted a study involving 140 male weight lifters who had either taken steroids for two or more years or not taken steroids at all, and their researchers assessed their heart function compared with tests on their arteries.

Steroid users had stiffer hearts that did not fully relax between beats so oxygenated blood from the lungs couldn't fill up the main pumping chamber as effectively before next contraction contraction; scientists suspect long-term use can permanently damage heart function, and plan to analyze whether normality returns after cessation of usage.

Does TRT Have an Effect on the Heart?

Testosterone has long been associated with muscular bodybuilders at risk of heart complications. This stigmatisation has caused testosterone prescriptions and usage rates to decline significantly; however, recent meta-analyses have concluded that short and medium-term TRT does not increase heart disease risk.

There are no large, long-term, placebo-controlled, randomized trials that can provide definitive conclusions on TRT and CV risks. 

There is an extensive amount of literature that dates back several decades and provides valuable information. 

Numerous studies have shown that low serum levels of T are associated with an increased risk for CV disease and mortality, and that TRT could have clinically significant CV benefits.

Studies of various kinds and lengths found that those using daily testosterone gel did not experience any additional major cardiovascular issues than those using placebo gel for up to three years - an encouraging outcome that should put any worries or reservations about using testosterone to rest.

Hypotheses regarding how T could protect against CVD have been put forth, including vasodilatory effects of endothelial nitric oxide and ATP-sensitive potassium channels in vascular smooth muscle cells, and its inhibition of atherosclerosis by lowering lipidemia, decreasing inflammation, lowering insulin resistance and blood glucose levels, as well as protecting against atherosclerosis itself.

Testosterone's trophic effect on skeletal muscle also increases exercise capacity in patients with chronic heart failure and improves serum glucose levels, hemoglobin A1C levels and insulin resistance in diabetics - all factors which contribute to cardiovascular disease development, thus giving T an additional benefit beyond its libido-enhancing, sexual function boosting and energy boosting properties.

A 2008 study involved giving either oral testosterone or placebo to coronary artery patients who had low testosterone levels and suffered from coronary artery disease, respectively.

While testosterone treatment modestly increased blood flow by widening healthy but partially blocked coronary arteries, it did not significantly alleviate angina symptoms or decrease HDL cholesterol and triglycerides levels significantly.

Testosterone Replacement Therapy is a safe and effective treatment option for men at risk for cardiovascular disease who have low testosterone.

While concerns have been expressed regarding increasing heart disease risk with testosterone therapy, recent studies indicate that short or medium-term treatments lasting less than 12 months do not increase this risk - they may even improve cardiovascular physiology and function!

Implementation of TRT may be even more effective when combined with regular physical activity and healthy diet habits.

TRAVERSE research proved that testosterone replacement therapy does not result in an increased rate of major adverse cardiovascular events in men with preexisting heart disease or high risk for it, an important finding that allayed any concerns regarding its use for treating hypogonadism.

Furthermore, testosterone has shown protective benefits against exercise-induced myocardial infarction (heart attack) among older men; more research must be conducted to understand why and how testosterone acts this way.

Are Injections Safer than other Modes of TRT?

TRT administered by injection is more effective than TRT administered transdermally or oraly for older hypogonadal males. 

The musculoskeletal benefit is greater due to the higher doses given im as opposed to transdermally. 

Intramuscular TRT, despite the higher doses, may not have the same CV risk as transdermal TRT. 

This phenomenon could be explained by the fact that transdermal TRT causes a greater elevation in serum DHT due to the expression of 5a reductase on skin but not muscle. 

To date, meta-analysis of existing placebo-controlled randomized trials has not been sufficient to assess definitively the CV effects TRT. 

Existing data show trends that indicate that TRT might not accelerate prostate cancer in early stages, that transdermal treatment may increase CV risk and that intravenous TRT could have a CV benefit.


Testosterone levels naturally decline with age, increasing risk for heart disease. Testosterone replacement therapy (TRT) is an increasingly popular way to restore healthy testosterone levels among older men in order to boost energy, muscle mass gain and libido; and may even help alleviate sleep disorders, sexual issues or joint pain.

TRT is often an ongoing treatment, so those on TRT should have regular checkups every 6-12 months. TRT typically has a positive impact on body health and benefits may include increased lean muscle mass, energy increases, better sleep quality and an improvement in your immune system as well as an increase in sexual libido. Furthermore, you will experience greater physical activity while experiencing greater well-being overall.

The use of testosterone replacement therapy (TRT), has been shown in studies to improve the myocardial ischemia and exercise capacity for men with CAD and CHF. It also improves serum glucose, HbA1c and insulin resistance among men with diabetes or prediabetes. 

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