hormoneInjectableControlledSchedule III (US)Prescription only (US)
Testosterone CypionateBenefits, Dosage & Interactions
Also known as: Test Cyp, Depo-Testosterone
Testosterone cypionate is an esterified form of the androgen testosterone, a naturally occurring steroid hormone primarily produced in the testes of males and in smaller amounts in the ovaries of females and adrenal glands in both sexes. As a medication, it is categorized as an androgen and an anabolic steroid.
How much Testosterone Cypionate do people take?
The Testosterone Trials titrated to a mid-normal serum testosterone rather than a fixed amount; product labels describe 50–400 mg every 2 to 4 weeks. Route reported: Intramuscular (and off-label subcutaneous) injection. Frequency reported: Every 1 to 4 weeks depending on the regimen. These are amounts documented in the cited studies and labels for Testosterone Cypionate — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Moderate — One published human randomized trial; results not yet replicated.
Evidence strengthModerate · 3/4
PreclinicalStrong human evidence
One published human randomized trial; results not yet replicated.
Plasma half-life
~192 h
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Reported amounts
- The Testosterone Trials titrated to a mid-normal serum testosterone rather than a fixed amount; product labels describe 50–400 mg every 2 to 4 weeks[1]
- Route studied
- Intramuscular (and off-label subcutaneous) injection[1]
- Frequency
- Every 1 to 4 weeks depending on the regimen[1]
- Cycle length
- Continuous therapy; 12 months in the Testosterone Trials[1]
- Half-life
- Approximately 8 days for the cypionate ester[1]
- Storage
- Room temperature, protected from light[1]
Reported for Testosterone Cypionate in the cited sources. Published ranges are not dosing advice.
Mixing Testosterone Cypionate: bacteriostatic water and syringe units
The vial arrives as dry powder. How much water you add sets the strength, and the strength sets the mark you draw to on the syringe. The table assumes a 5 mg vial and a 250 mcg example draw on a U-100 insulin syringe, where 100 units is one millilitre. If your vial is a different size, scale it — the arithmetic is the same.
| Bacteriostatic water added | Resulting strength | 250 mcg draws to |
|---|---|---|
| 1 mL | 5 mg/mL | 5 units |
| 2 mL | 2.5 mg/mL | 10 units |
| 3 mL | 1.67 mg/mL | 15 units |
Units, not millilitres. Insulin syringes are marked in units, and mixing up mcg and mg on a peptide label is the single most common error people report. Check the label twice. Run your own vial through the calculator.
Storage and stability
- Before mixing
- Sealed and still as a dry powder, Testosterone Cypionate vials are normally kept in the fridge at 2–8 °C, out of light. Short spells at room temperature during shipping are the norm for lyophilized peptides and are not, on their own, a sign the vial is spoiled.
- After mixing
- Once bacteriostatic water goes in, the vial belongs in the fridge and is generally treated as good for about 28 days — that is how long the benzyl alcohol in bacteriostatic water is relied on to hold back bacterial growth. Plain sterile water has no preservative, so a vial mixed with it is a single-session vial. Never freeze a reconstituted vial.
- When to throw it out
- A properly mixed vial is clear. Cloudiness, floating strands, a color change or powder that will not go into solution after gentle swirling all mean the vial should be discarded rather than used. Shaking a peptide vial hard is the usual cause — swirl it, or run the water down the inside wall of the vial instead of onto the powder.
Handling and shelf-life figures describe general practice for lyophilized peptides. They are not a dose and not medical advice — your prescriber or the product label sets the amount.
References & evidence
Documents the Testosterone Cypionate entry is written from. Each number matches an inline marker above.
- [1]Effects of Testosterone Treatment in Older MenSnyder PJ, Bhasin S, Cunningham GR, et al. · New England Journal of Medicine · 2016 · Peer-reviewed · PMID 26886521
References & Evidence
Sources on this page that document Testosterone Cypionate dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Testosterone Cypionate studied for?
What is Testosterone Cypionate?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Testosterone cypionate is an esterified form of the androgen testosterone, a naturally occurring steroid hormone primarily produced in the testes of males and in smaller amounts in the ovaries of females and adrenal glands in both sexes. As a medication, it is categorized as an androgen and an anabolic steroid. It is commonly administered via intramuscular injection and is designed for a sustained release of testosterone, providing a relatively stable level of the hormone over an extended period. This sustained-release property is due to the cypionate ester, which is slowly cleaved from the testosterone molecule *in vivo*, converting it into bioactive testosterone. The primary medical application of testosterone cypionate is in testosterone replacement therapy (TRT) for men diagnosed with hypogonadism, a condition characterized by insufficient testosterone production. It is also used in certain cases for delayed puberty in boys and for specific types of breast cancer in women. (Source: DrugBank, MedlinePlus)
What does the research say about Testosterone Cypionate?
Tap a section to expand.
Testosterone cypionate functions as a prodrug. After intramuscular injection, the cypionate ester slowly hydrolyzes, releasing free testosterone. This free testosterone then binds to androgen receptors located in various tissues throughout the body, including muscle, bone, skin, brain, and prostate. Upon binding, the testosterone-receptor complex translocates to the cell nucleus, where it interacts with specific DNA sequences (androgen response elements) to influence gene expression. This leads to the synthesis of proteins responsible for the development and maintenance of male secondary sexual characteristics, anabolism, and other testosterone-dependent physiological processes. Testosterone can also be metabolized into dihydrotestosterone (DHT) by the enzyme 5-alpha-reductase, which is a more potent androgen, and into estradiol by the enzyme aromatase. Both DHT and estradiol also exert biological effects within the body. The half-life of testosterone cypionate, due to its esterification, is approximately 192 hours, contributing to its prolonged action. (Source: DrugBank, PubChem)
Source for this section: Sources for How does Testosterone Cypionate work?: Jumps to this entry in the sources and references list at the end of the page.
In individuals with clinically diagnosed testosterone deficiency (hypogonadism), testosterone cypionate therapy can lead to several documented benefits related to the restoration of physiologic testosterone levels. These benefits often include improvements in:
* **Sexual Function:** Increased libido, improved erectile function, and overall sexual satisfaction. (Source: NIH ODS, DrugBank)
* **Bone Mineral Density:** Increased bone density, which can help reduce the risk of osteoporosis, especially in older men. (Source: Mayo Clinic)
* **Body Composition:** Increased lean muscle mass and decreased fat mass. (Source: Cochrane Review)
* **Mood and Cognition:** Potential improvements in mood, reduction in symptoms of depression, and enhanced cognitive function in some individuals. (Source: MedlinePlus)
* **Energy Levels and General Well-being:** Patients often report increased energy, vitality, and an overall sense of well-being. (Source: FDA prescribing information)
* **Red Blood Cell Production:** Stimulation of erythropoiesis, leading to an increase in red blood cell count and hemoglobin levels, which can be beneficial in addressing anemia associated with hypogonadism. (Source: DrugBank)
It is crucial that these benefits are weighed against potential risks and are only pursued under strict medical supervision for legitimate medical indications.
Extensive clinical evidence from randomized controlled trials and observational studies supports the use of testosterone cypionate in the treatment of male hypogonadism. Studies consistently demonstrate its efficacy in normalizing serum testosterone levels and alleviating the symptoms associated with low testosterone. For instance, a meta-analysis cited by the Endocrine Society guidelines indicates significant improvements in sexual function, body composition, and bone mineral density in hypogonadal men undergoing testosterone replacement therapy. The long-acting nature of testosterone cypionate, as an ester, has been shown to produce more stable serum testosterone concentrations compared to shorter-acting formulations, which can contribute to better symptom control and fewer fluctuations in mood or energy. Research also highlights the importance of individualizing treatment, monitoring hormone levels, and assessing patient response to therapy. (Source: Cochrane Review, NIH ODS, MedlinePlus)
Common side effects associated with testosterone cypionate can include:
* **Injection site reactions:** Pain, swelling, or redness at the site of intramuscular injection.
* **Acne or oily skin:** Increased sebaceous gland activity.
* **Fluid retention:** Swelling (edema) in the ankles, feet, or other parts of the body.
* **Changes in libido:** While often positive, some individuals may experience unwanted changes.
* **Mood changes:** Including irritability, anxiety, or depression.
* **Headaches.**
* **Hair loss or male pattern baldness.**
* **Gynecomastia:** Development or enlargement of breast tissue in men.
* **Changes in laboratory values:** Such as elevated red blood cell count (erythrocytosis), alterations in lipid profiles, and liver enzyme elevations.
Less common but more serious side effects may include:
* **Sleep apnea:** Worsening or development of sleep apnea.
* **Prostate enlargement:** Exacerbation of benign prostatic hyperplasia (BPH) symptoms.
* **Increased risk of prostate cancer detection:** Testosterone therapy can accelerate the growth of existing, undiagnosed prostate cancer.
* **Cardiovascular events:** Some studies have suggested a potential link to an increased risk of heart attack, stroke, and cardiovascular death, though this remains an area of ongoing research and debate. (Source: FDA prescribing information, Mayo Clinic)
This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Testosterone cypionate carries several important warnings. It should be used with extreme caution in individuals with pre-existing cardiovascular disease, as there have been concerns regarding a potential increased risk of adverse cardiovascular events such as myocardial infarction and stroke. Patients with a history of heart failure, renal impairment, or hepatic impairment may experience fluid retention, leading to or exacerbating edema. Regular monitoring of hemoglobin and hematocrit levels is crucial due to the risk of erythrocytosis, which can increase blood viscosity and the risk of thromboembolic events. Male patients should undergo prostate cancer screening (PSA and DRE) before starting treatment and periodically thereafter, as testosterone therapy can stimulate the growth of pre-existing prostate cancer. Patients with sleep apnea should be monitored closely, as testosterone can worsen this condition. It is also important to be aware of the potential for abuse and dependence, particularly in non-medical settings, due to its anabolic properties. The use of testosterone cypionate in children requires careful consideration due to the risk of accelerated bone maturation and premature epiphyseal closure. (Source: FDA prescribing information, MedlinePlus) This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Testosterone cypionate is contraindicated in several conditions:
* **Known or suspected prostate cancer:** Testosterone can stimulate the growth of prostate cancer.
* **Male breast cancer:** Due to the hormonal nature, it is contraindicated in breast cancer in men.
* **Pregnancy and breastfeeding:** Testosterone cypionate can cause fetal harm and is contraindicated in pregnant or breastfeeding women.
* **Hypersensitivity:** Individuals with a known hypersensitivity to testosterone cypionate or any components of the formulation.
* **Serious cardiac, hepatic, or renal disease:** Due to the risk of fluid retention and potential exacerbation of these conditions. (Source: FDA prescribing information, DrugBank)
This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Testosterone cypionate can interact with various medications, potentially altering their effects or increasing the risk of adverse reactions. Key interactions include:
* **Anticoagulants (blood thinners):** Testosterone can enhance the anticoagulant effect of warfarin and similar medications, increasing the risk of bleeding. Close monitoring of INR and prothrombin time is necessary.
* **Corticosteroids:** Concomitant use may increase the risk of edema, particularly in individuals with pre-existing cardiac, hepatic, or renal disease.
* **Insulin and oral antidiabetic agents:** Testosterone can improve glucose tolerance and decrease blood glucose levels, potentially requiring dosage adjustments of antidiabetic medications to prevent hypoglycemia.
* **Thyroid hormones:** Testosterone may decrease levels of thyroid-binding globulin, potentially leading to increased free thyroid hormone levels. This may necessitate a reduction in thyroid hormone dose in patients on thyroid replacement therapy.
* **Cyclosporine:** There is some evidence suggesting testosterone may increase cyclosporine levels, leading to increased toxicity.
* **Diuretics:** Co-administration may reduce the natriuretic effect of diuretics due to sodium and fluid retention caused by androgens.
* **Erythropoiesis-stimulating agents:** Given that testosterone can also stimulate erythropoiesis, concurrent use might lead to excessive increases in red blood cell count.
This is not an exhaustive list, and other interactions may exist. Always inform your healthcare provider about all medications, supplements, and herbal products you are using. This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Testosterone cypionate is an injectable medication usually administered intramuscularly. The typical dosing schedule involves injections every 1 to 4 weeks, with the most common frequency being every 2 weeks. This extended interval is a benefit of the cypionate ester, which allows for a slow and sustained release of testosterone, maintaining relatively stable hormone levels between doses. Individual response and symptom management guide the specific injection frequency and dose, which is user-directed and must be set by a licensed clinician. It can be injected at any time of day, as its long-acting nature means acute timing relative to meals or daily rhythms is not a primary concern. Consistency in the injection schedule is important for maintaining stable blood levels of testosterone. (Source: FDA prescribing information, NIH ODS)
Source for this section: Sources for When should you take Testosterone Cypionate?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Testosterone Cypionate is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Testosterone Cypionate?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any peptide + hormone | Note | Category ruleConfidence: theoretical | Injectable peptides plus hormones can have overlapping or compounding effects that aren't always well characterized.Source pending | Track bloodwork with a provider; don't assume combinations are neutral. |
| Any + | Complementary | Category ruleConfidence: theoretical | AI manages estradiol on TRT.Source pending | Titrate AI to target mid-range E2 with bloodwork every 6–8 weeks. |
| HCG | Complementary | Compound pairConfidence: theoretical | HCG maintains intratesticular testosterone and testicular size during exogenous testosterone use.Source pending | Typical protocol: 250–500 IU HCG 2–3× weekly alongside TRT. |
| Finasteride | Caution | Compound pairConfidence: theoretical | 5-alpha-reductase inhibitors block DHT conversion; can affect libido and prostate response on TRT.Source pending | Discuss goals with prescribing clinician; monitor sexual function. |
| Dutasteride | Caution | Compound pairConfidence: theoretical | 5-alpha-reductase inhibitors block DHT conversion; can affect libido and prostate response on TRT.Source pending | Discuss goals with prescribing clinician; monitor sexual function. |
Frequently asked questions about Testosterone Cypionate
Testosterone cypionate is primarily used for testosterone replacement therapy in men diagnosed with hypogonadism, a condition where the body does not produce enough testosterone. It helps restore hormone levels and alleviate symptoms associated with low testosterone.
Testosterone cypionate is administered via intramuscular injection, typically into a large muscle like the gluteal muscle. The cypionate ester allows for a slow release, meaning injections are usually given every 1 to 4 weeks.
Common side effects can include pain at the injection site, acne, fluid retention, mood changes, and an increase in red blood cell count. More serious side effects can also occur, and individuals should discuss these with their clinician.
While testosterone levels are important in women, testosterone cypionate is primarily prescribed for men. In rare medical cases, low doses might be used in women for specific conditions like certain types of breast cancer, but it's generally not a common treatment for female hormone imbalances due to the risk of virilization.
Yes, testosterone cypionate is classified as a Schedule III controlled substance in the United States due to its potential for abuse and dependence, particularly in non-medical contexts for performance enhancement. It requires a prescription from a licensed clinician.
Interaction risk for Testosterone Cypionate comes from the rest of the stack: other hormones, prescription medicines, hormone therapy and peptides. With a reported plasma half-life near 192 hours, separating doses can change the picture as much as removing one. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Testosterone Cypionate with no sign-up.
Testosterone Cypionate is administered by injection, so the measured volume — not a tablet count — is the unit that matters. The reported plasma half-life is about 192 hours, which is what drives how often it is redosed. It is a controlled substance in some jurisdictions, so the prescribed amount is the only appropriate one. Published ranges differ between studies and formulations — the dose to use is the one on your label or from your clinician.
There is no single answer for Testosterone Cypionate plus TRT. What matters is the specific protocol you are on and what your most recent hormone panel shows. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Pairing Testosterone Cypionate with peptides has to be assessed one peptide at a time, because GLP-1 agonists, secretagogues, healing peptides and melanocortins do not share an interaction profile. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
A long plasma half-life of about 192 hours means Testosterone Cypionate is commonly dosed every few days or weekly rather than daily. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
With a plasma half-life near 192 hours, a single missed dose of Testosterone Cypionate usually has a smaller effect on overall exposure than an irregular pattern of missed doses does. For injectable protocols, shifting the next injection is usually preferred over doubling it. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For an injectable like Testosterone Cypionate the record needs more than a checkbox: vial concentration, the measured volume, and which site the last injection went into. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
The Testosterone Trials titrated to a mid-normal serum testosterone rather than a fixed amount; product labels describe 50–400 mg every 2 to 4 weeks. Route reported: Intramuscular (and off-label subcutaneous) injection. Frequency reported: Every 1 to 4 weeks depending on the regimen. These are amounts documented in the cited studies and labels for Testosterone Cypionate — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Testosterone Cypionate?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Recommendations for the Use of Testosterone in Male Transgender(opens PubMed in a new tab)Rev Bras Ginecol Obstet · 2018 · PMID 29913543 · https://pubmed.ncbi.nlm.nih.gov/29913543/
- 2.Testosterone Treatment in Prostate Cancer Survivors With Hypogonadism: A Randomized Clinical Trial(opens PubMed in a new tab)JAMA Intern Med · 2026 · PMID 42113507 · https://pubmed.ncbi.nlm.nih.gov/42113507/
- 3.Effect of 100 mg of testosterone cypionate in trans men with erythrocytosis: a randomized controlled pilot study(opens PubMed in a new tab)J Sex Med · 2025 · PMID 41052128 · https://pubmed.ncbi.nlm.nih.gov/41052128/
- 4.The Effect of Route of Testosterone on Changes in Hematocrit: A Systematic Review and Bayesian Network Meta-Analysis of Randomized Trials(opens PubMed in a new tab)J Urol · 2022 · PMID 34445892 · https://pubmed.ncbi.nlm.nih.gov/34445892/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 441404(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/441404
Verify at
Publisher search links for Testosterone Cypionate. These are places to check the information — they are not citations, so they are not numbered.
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Testosterone Cypionate?
Plain-text summary, safe to quote verbatim:
Testosterone cypionate is an esterified form of the androgen testosterone, a naturally occurring steroid hormone primarily produced in the testes of males and in smaller amounts in the ovaries of females and adrenal glands in both sexes. As a medication, it is categorized as an androgen and an anabolic steroid.
Source: DoseRoutine — https://doseroutine.com/library/testosterone-cypionate
Testosterone Cypionate cheat sheet
DoseRoutine cheat sheet · Hormone
Testosterone Cypionate
Testosterone cypionate is an esterified form of the androgen testosterone, a naturally occurring steroid hormone primarily produced in the testes of males and in smaller amounts in the ovaries of females and adrenal glands in both sexes. As a medication, it is categorized as an androgen and an anabolic steroid.
Evidence
Moderate
One published human randomized trial; results not yet replicated.
Studied range
The Testosterone Trials titrated to a mid-normal serum testosterone rather than a fixed amount; product labels describe 50–400 mg every 2 to 4 weeks
Route
Intramuscular (and off-label subcutaneous) injection
Frequency studied
Every 1 to 4 weeks depending on the regimen
Half-life
~192 h
Storage
Room temperature, protected from light
Schedule III (US)Prescription only (US)TestosteroneBrainBone JointLibido
Key references
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/testosterone-cypionate
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Testosterone Cypionate — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/testosterone-cypionate
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