Testosterone Cypionate

Depo-Testosterone

Testosterone TRT HRT aas IM SubQ FDA/EMA Label

Half-life

8 days

Time to Peak

36 hr

Steady State

~40 days

Bioavailability

100%

Dose Range

50–300 mg

Frequency

Weekly

Overview

Testosterone Cypionate is the most commonly prescribed testosterone ester in the US for TRT. It's an oil-based injectable with a half-life of about 8 days, allowing for weekly or twice-weekly dosing.

Mechanism of Action

Depot injection releases testosterone via ester hydrolysis. Testosterone binds androgen receptors, promoting anabolic effects and maintaining male sex characteristics.

Dosing Information

Route Dose Range Half-life Tmax Frequency
Intramuscular (IM) 50–300 mg 8 days 36 hr Weekly, Every 2 weeks, Twice weekly
Subcutaneous (SubQ) 25–200 mg 8 days 2 days Twice weekly, Every other day, Weekly

Common Side Effects

  • · Acne
  • · Hair thinning (androgenic alopecia)
  • · Increased hematocrit/polycythemia
  • · Elevated estradiol (aromatization)
  • · Testicular atrophy (without HCG)
  • · Injection site pain (PIP)
  • · Mood changes
  • · Sleep apnea (rare)

Monitoring Recommendations

Total T, Free T, Estradiol (sensitive), CBC with hematocrit, and PSA every 3-6 months for the first year, then annually. Lipid panel at baseline and annually. Liver function tests at baseline.

Storage & Handling

Room Temperature

Store at 20-25°C (68-77°F). Excursions permitted 15-30°C.

General

Protect from light. Do not refrigerate or freeze. Discard multi-dose vials 28 days after first puncture per USP <797>.

Community Notes

SubQ injection is increasingly popular — smaller needle, less PIP, similar absorption. Most TRT-optimized protocols use 2x/week to reduce estradiol spikes and keep levels more stable. Warming the oil to body temperature before injecting reduces viscosity and PIP.

Used in Regimens

11 regimens

Beginner First Cycle (Harm Reduction)

Conservative beginner AAS cycle for harm reduction: testosterone-only at moderate dose with on-cycle HCG and post-cycle Nolvadex. Designed to minimise risk while providing meaningful data about individual response to testosterone before adding other compounds.

Test Cyp 300mg/week (lower than community 500mg — harm reduction dose).

18wk Harm Reduction aas
Primary

Beginner Test-Only Blast + PCT

12-week testosterone cypionate blast at beginner doses with on-cycle HCG for testicular maintenance, followed by a 2-week clearance window and 4-week Nolvadex PCT. The gold-standard first cycle.

18wk Harm Reduction trt aas
Primary

Blast and Cruise

Alternating between a blast (supraphysiological testosterone dose for 8–16 weeks) and a cruise (return to TRT dose indefinitely). Avoids the PCT phase entirely. Common among experienced TRT users and advanced bodybuilders who do not intend to discontinue testosterone.

Blast phase: beginner blast protocol 300–500mg/week for 12 weeks.

Harm Reduction trt aas
Primary

Daily SubQ Micro-Dose TRT

Testosterone cypionate administered daily subcutaneously at low volume (0.1–0.15mL/day). Produces the most stable serum testosterone and oestradiol levels of any injectable protocol, closely mimicking the natural circadian rhythm. Favoured by those sensitive to hormonal fluctuations.

Daily micro-dose SubQ. Typical total weekly dose 70–140mg split 7 ways.

trt
Primary

Low-Dose Testosterone — Non-Binary / Microdose

Testosterone cypionate or enanthate at micro-dose (typically 20–50mg/week) for non-binary, genderqueer, or transmasculine individuals seeking partial masculinisation. Lower doses produce selective changes — increased libido and clitoral growth typically first; voice changes and significant hair growth require higher doses and longer duration.

Transmasc T Cyp microdose protocol 20–50mg/week.

hrt_masc
Primary

Standard TRT Protocol

Evidence-based testosterone replacement with HCG for testicular maintenance and optional low-dose aromatase inhibitor. The most common TRT stack recommended by progressive clinicians.

trt
Primary
See all 11 regimens →

Data Sources

Related Tools

Track Testosterone Cypionate with Doseline

Reminders, medication level charts, injection site rotation, and protocol tracking — all free, all private.

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Doseline provides informational tools only. It is not a medical device and does not provide medical advice. Always consult a qualified healthcare provider.

Doseline provides informational tools only. It is not a medical device and does not provide medical advice. Always consult a qualified healthcare provider.