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TRT Explained: 101 Guide on Testosterone Replacement Therapy

Written by

Science & Humans

Medically approved by

Maria Jacob

Last updated

Friday, August 12, 2022

TRT Therapy or (TRT) Testosterone Replacement Therapy. TRT therapy raises/replaces low testosterone levels, caused by hypogonadism or low-T. Testosterone is an essential male androgen that defines male characteristics, libido, muscle mass, fertility, sense of well being and bone health. Primary hypogonadism and secondary hypogonadism both area a result of low testosterone. Testosterone levels peaks in puberty and tapers down by 1%/ a year from age 30 onwards.

What Kind of a Doctor/Specialist to see for TRT Therapy?

A specialist called an endocrinologist trained in the endocrine system of the body which mainly deals with hormones and their effects is qualified to diagnose and prescribe TRT therapy.

How is Hypogonadism (low-T) Diagnosed?

A blood test which looks at many factors including serum testosterone levels. The bound and unbound testosterone is measured. Most of the testosterone is bound by SHBG(Sex Hormone Binding Globulin) early morning when testosterone is at its peak in the body.

The blood sample should be collected in the morning, preferably before 10AM, or within 3 hours of waking, and preferably in a fasting state.

The test might be repeated for consistency and accuracy to determine the range of natural testosterone so the correct dosage and frequency can be determined.

Blood samples must be collected in the morning, preferably before 10AM, or within 3 hours of waking, and preferably in a fasting state.

Circulating testosterone exists in three forms: free, weakly bound to albumin, and strongly bound to SHBG. Serum total testosterone measures all three forms.

Bioavailable testosterone is the sum of free testosterone and albumin bound testosterone.

Bioavailable and free testosterone results may be calculated or directly measured.

Calculated bioavailable testosterone or cBAT and calculated free testosterone are arrived at utilizing both measured total testosterone and measured SHBG concentrations.

While these two parameters may be reported separately, both are functionally and diagnostically equal and same.

It is better to use the same lab for initial and follow up testosterone tests because reference ranges are lab-dependent. The reference ranges might not be comparable from different labs.

Symptoms of Hypogonadism or Low-T

Loss of testosterone manifests in many ways ranging from low libido, mood swings , brain fog to brittle bones, increase in fat mass, loss of muscle tone and mass, lacking sense of well being etc.



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Is TRT Therapy Different from TRT?

TRT therapy is the same as TRT or Testosterone Replacement Therapy.

Also known as Androgen Replacement Therapy(ART)

Benefits of TRT therapy?

Benefits of TRT therapy, replacing extremely low testosterone levels restores sense of wellbeing, boosts energy levels, sex drive, sharpens mental faculty, bonus – loss of fat mass and improved muscle mass, bone mineral density as well.

How safe is TRT therapy?

Testosterone therapy is extremely safe, has been administered for decades, well researched and side effects documented.

Treatment protocols of quarterly check ups monitor for increased RBC counts, PSA levels, any other comorbidities/disease/condition captured in initial medical history will be monitored as well.

Continuing research reveals testosterone’s beneficial properties in other aspects of male health as well.

Some studies even suggest treating depressed men with higher doses of testosterone to treat depression.

Different types of Testosterone used for TRT therapy

Testosterone by itself will metabolize quickly in hours. It is usually injected as an ester where oil is used to slow down the absorption process. Different types of carrier oils are used for esterification. Cotton seed oil, Castor oil, Olive oil, common while Tea Tree oil and others are also used.

Testosterone injections are given intramuscular- in the buttock muscle or on the deltoids in the arm. Subcutaneously, which means injecting under the skin.

These are the testosterone esters/generics used for testosterone injections/ shots:

  • Cypionate
  • Enanthate
  • Propionate
  • Undecanoate

Cypionate and enanthate esters are the most popular, widely used testosterone esters for treating low-T symptoms. With a similar chemical structure and half life, it can be used interchangeably without any issues. Cypionate lasts slightly longer than enanthate.

Propionate is a slow-releasing form of testosterone with a half-life of 4.5 days. It requires frequent injections, since it is metabolized quickly. Blood plasma levels peaks quickly within hours of injecting. While T-levels are stabilized rapidly the negatives of aromatization into estrogen, higher peaks and valleys does not make it an ideal testosterone injection compared to enanthate or Cypionate. It is prescribed for special cases. The pros and cons should be weighed carefully for a Propionate injection regimen.

Undecanoate This testosterone ester is used in Europe more than the US. FDA has approved an oral testosterone pill of undecanoate for men with low testosterone levels due to specific medical conditions, such as Klinefelter syndrome or tumors that have damaged the pituitary gland.

This oral testosterone undecanoate (Jatenzo, Clarus Therapeutics) should not be used to treat men with age related hypogonadism in which testosterone levels decline due to aging, even if these men have symptoms that appear to be related to low testosterone, according to the FDA, which stated that the drug’s benefits do not outweigh its risks for that use.

Testosterone suspension which is only testosterone crystals in water and no esters is used by bodybuilders to build muscle mass. It is the most powerful injectable steroid that quickly adds muscles and increases strength. It is extremely painful, requires frequent IM injections since it metabolizes in hours. There is no “ester” to control the release and make it last longer in the body. The risks are higher for treating low T and is not a recommended mode of treatment for low-T.

Custom blends of multiple esters of testosterone targeting different health goals and depending on an individual’s tolerance to the carrier oil, preservative used, other health conditions if any are also pursued for enhanced outcomes. This has to be discussed with the doctor. Also this is something to be looked at after using regular testosterone treatments for a while.

How long should TRT Therapy be Taken?

Different symptoms of low-testosterone take a range of 3 weeks to a year to improve.

TRT therapy is a life long treatment since TRT only replaces testosterone which the body is not producing daily in adequate quantity required.

What Happens if TRT Therapy is Stopped?

Depending on the testosterone ester used, and the duration of treatment, the body will revert to the low levels of Testosterone before starting therapy. If clomid or HCG was part of the regimen the T-levels will recover faster since HCG prevents shrinking of testicles due to non-use or atrophy while on Testosterone therapy.

Symptoms of low energy, no or low libido, mood swings, increase in fat gain, losing muscles can recur.

For fertility reasons sometimes TRT therapy is stopped for a period to improve sperm generation, and therapy resumes post conception.

TRT Therapy Dosage

Testosterone is prescribed in doses necessary for the body to function well, and the replacement dose is calibrated based on an individual’s needs, to treat low-T symptoms.

Testosterone injection dosage is based on several factors like frequency, injecting via IM(Intramuscular) or SubQ(subcutaneously).

Higher doses are used by bodybuilders to bulk up and build muscle. Both categories use the same testosterone esters like Cypionate and Enanthate.

Dosage is also determined on the kind of regimen and the ester of testosterone. If one is on a micro-dosing schedule injections will be more frequent but comparatively lesser dose than if on a regular schedule.

Typically doses are 200 ML/week to 10 days for enanthate and cypionate, which are the most widely used esters for treating low -T.

Is TRT Therapy Legal?

TRT therapy is legitimate and medication of testosterone injections or creams(most popular treatments) is only by prescription after a clinician diagnosis of low-T or hypogonadism via blood tests.

Skin implants, patches, nasal gel are other testosterone treatments.

Cost of TRT Therapy, With and Without Insurance

Insurance pays for generic testosterone injections and cheapest, while creams & gels are expensive and not covered by insurance. Expect a range of 20.00$ to a 1000.00$ monthly out of pocket, depending on location and insurance coverage.

Cypionate and Enanthate are the most popular generic esters of testosterone prescribed. Insurance covers both.

TRT Therapy – Side Effects

With quarterly medical check ups, and doctor monitoring blood levels, TRT therapy is extremely safe and side effects highly manageable with benefits outweighing risks.

Heart issues, PSA most common to watch out for.

How Soon Will TRT Therapy Show Results?

3 months of TRT therapy must for an overall before and after result.

Treatment either by injections or creams with minor differences. Creams lift mood & sexual interest faster while injections build muscle quicker.

Custom compounded scrotal creams also benefit those suffering low libido, mild ED symptoms. Since the scrotal skin is thin and highly permeable, it absorbs the cream faster for a quicker libido boost. Only custom compounded scrotal creams will not cause rashes or itching since it does not have alcohol.

Libido, sexual interest quickest, quality of life – 3 weeks
Quality of erections, ejaculation, easing depression – 3 to 6 weeks
Fat mass reduction, lean body & muscle strength – 12 to 16 weeks

Reducing inflammation - 3 to 12 weeks
Bone density - 6 months to an year

Insulin sensitivity within few days, Glycemic control – 3 to 12 months.

Further reading

Understanding the Importance of Regular Testosterone Checks

Understanding the Importance of Regular Testosterone Checks

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Understanding Testosterone: Key Male Hormone

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