BHRC BLOG
hCG on TRT: Dosage, Mixing Chart and hCG vs. Gonadorelin
Medically reviewed by the BHRC Clinical Team · Last reviewed 2026-11-14
Testosterone therapy works well for symptoms, but it switches off the signal your testes need to make sperm and their own testosterone. Over months, sperm count falls, often to zero, and the testicles shrink. Low-dose hCG is the most widely used and best-studied way to prevent that while staying on TRT.
This guide covers the hCG doses used with TRT, how to mix it and convert international units (IU) into syringe units, side effects and monitoring, and how hCG compares with gonadorelin and enclomiphene.
Important: hCG is a prescription medication. Using it alongside testosterone therapy is off-label, and hCG is not approved or effective for weight loss. Since 2020 only FDA-licensed hCG products (such as Pregnyl and Novarel) can be dispensed; compounded hCG is no longer permitted. This guide is educational and is not a substitute for medical advice.
Quick hCG on TRT Dosing Summary
The standard dose of hCG alongside TRT is 500 IU injected under the skin 2-3 times per week (250-500 IU per dose), which keeps the testes producing sperm and their own testosterone while you’re on testosterone therapy.
- Typical dose with TRT: 500 IU SubQ 2-3 times weekly, or every other day
- Common mix: 5,000 IU + 5 mL bacteriostatic water = 1,000 IU/mL, so 500 IU = 0.5 mL = 50 units
- Products: Novarel 5,000 units and Pregnyl 10,000 units (FDA-licensed)
- Storage: Refrigerate after mixing; use within the period on the package insert
- What we monitor: Testosterone, estradiol, hematocrit, testicular size, and semen analysis if you’re trying to conceive
- hCG for weight loss?: No. hCG has not been shown to help weight loss, and we don’t prescribe it for that.
Why Add hCG to TRT?
Your pituitary releases LH, which tells the Leydig cells in the testes to make testosterone. That testosterone inside the testes is roughly 50-100 times higher than in the blood, and it’s what drives sperm production. When you inject testosterone, the brain senses plenty and stops releasing LH. Testicular testosterone collapses, sperm production drops, and the testes shrink.
hCG is structurally similar to LH and binds the same receptor, so it stands in for the missing signal. In a study of men on TRT, adding 500 IU of hCG every other day kept semen parameters stable during follow-up, and none of the men lost sperm production entirely. Men use it to:
- Preserve fertility while on TRT
- Maintain testicular size and comfort
- Make it easier to restart natural production if they stop TRT later
A caveat: hCG lowers the risk but doesn’t guarantee fertility. Men actively trying to conceive should talk with their provider about stopping testosterone and using hCG or enclomiphene instead, and consider banking sperm before starting TRT.
hCG Dosage Chart for Men
Typical hCG dosing
| Goal | Dose | Frequency | Notes |
|---|---|---|---|
| Protect fertility and testicle size on TRT | 250-500 IU | 2-3 times weekly or every other day | Most common use |
| Restart after stopping TRT | 1,500-2,000 IU | 2-3 times weekly | Usually for a few months, often with enclomiphene or clomiphene |
| hCG alone for low T (no TRT) | 1,500-3,000 IU | 2-3 times weekly | Specialist-directed, mainly secondary hypogonadism |
Ranges reflect published urology practice and the AUA guideline. Higher doses raise estradiol more. Your provider sets your dose.
Many men inject hCG on the same days as their testosterone. Same-day injections are fine if your provider approves. If you’re on twice-weekly SubQ testosterone, a common schedule is hCG on Monday, Wednesday and Friday. See the testosterone cypionate guide for TRT dosing.
How to Mix hCG (and How Many Units to Draw)
hCG comes as a powder that must be mixed (reconstituted) with bacteriostatic water before use. Follow the mixing volume on your prescription. The examples below show how the math works.
- Wash your hands and wipe both vial tops with alcohol.
- Draw the prescribed volume of bacteriostatic water.
- Inject it slowly down the side of the hCG vial. Don’t spray it directly onto the powder.
- Swirl gently until dissolved. Don’t shake it.
- Label the vial with the date and refrigerate it.
hCG mixing and dose chart (U-100 insulin syringe)
| Vial + water | Concentration | 250 IU | 500 IU | 1,000 IU |
|---|---|---|---|---|
| 5,000 IU + 5 mL | 1,000 IU/mL | 0.25 mL = 25 units | 0.5 mL = 50 units | 1.0 mL = 100 units |
| 10,000 IU + 10 mL | 1,000 IU/mL | 0.25 mL = 25 units | 0.5 mL = 50 units | 1.0 mL = 100 units |
| 10,000 IU + 5 mL | 2,000 IU/mL | 0.125 mL = 12.5 units | 0.25 mL = 25 units | 0.5 mL = 50 units |
| 5,000 IU + 2.5 mL | 2,000 IU/mL | 0.125 mL = 12.5 units | 0.25 mL = 25 units | 0.5 mL = 50 units |
The math: IU dose ÷ IU per mL = mL to draw; mL × 100 = units. Insulin-syringe units are not the same as hCG international units (IU).
Storage: keep unmixed vials at room temperature. Once mixed, refrigerate (don’t freeze) and use within the time on the package insert, typically 30-60 days depending on the product.
How to Inject hCG
hCG is usually injected under the skin (SubQ) with a small insulin syringe (29-31G, ½ inch) into belly fat about two inches from the navel, or into the thigh. Rotate sites each time. It can also be given into the muscle, but small SubQ doses work well and are more comfortable. Your first injection is taught in clinic.
hCG vs. Gonadorelin vs. Enclomiphene
All three are used to keep the testes working, but they act at different points in the hormone chain and the evidence behind them is very different.
| hCG | Gonadorelin | Enclomiphene | |
|---|---|---|---|
| How it works | Acts like LH directly on the testes | Synthetic GnRH; tells the pituitary to release LH and FSH | Blocks estrogen feedback so the brain releases more LH and FSH |
| Use with TRT | Yes, the standard option | Used for this; evidence is limited | No; TRT suppresses the signal it needs |
| Evidence for fertility on TRT | Strongest | Limited | Used instead of TRT, not with it |
| Form | Injection 2-3 times weekly | Injection, often daily or twice daily | Daily capsule |
| FDA status | FDA-licensed (Pregnyl, Novarel); off-label for this use | Compounded; the FDA-approved version (Factrel) was discontinued | Not approved; compounded |
| Prescribed at BHRC | Yes | Yes (compounded) | Yes |
How we choose between hCG and gonadorelin: natural GnRH is released in pulses every 60-120 minutes and lasts only minutes in the blood. The strongest gonadorelin data come from men using infusion pumps that copy that pulse pattern, not from men on TRT using a few injections a week. hCG acts directly on the testes and has the stronger evidence for protecting sperm production on TRT, so it’s our usual first choice when fertility is the priority. Gonadorelin is an option for some men who want to keep the pituitary signal active, and your provider will explain the evidence gap before you choose.
For men who want to avoid testosterone entirely, see our enclomiphene dosage guide.
Side Effects and Monitoring
- Higher estradiol: hCG increases testosterone made inside the testes, and some converts to estrogen. Breast tenderness or puffy nipples usually means the dose is too high.
- Acne, oily skin and water retention, especially at higher doses
- Injection-site redness or soreness
- Headache, mood changes or fatigue
- Allergic reaction (rare): hives, swelling or trouble breathing need emergency care
Monitoring with hCG
| When | What we check |
|---|---|
| Before starting | Total T, LH, FSH, estradiol, CBC; semen analysis if fertility is a goal |
| 6-12 weeks | Total T, estradiol, hematocrit, symptoms, testicular comfort and size |
| Every 6-12 months | Total T, estradiol, hematocrit; semen analysis every 3-6 months if trying to conceive |
How We Prescribe hCG at BHRC
We bring up fertility before any man starts testosterone. If future children matter to you, you can start hCG alongside TRT from day one, use enclomiphene instead of TRT, or bank sperm first. We prescribe FDA-licensed hCG only (Novarel 5,000 units and Pregnyl 10,000 units) and teach mixing and your first injection in clinic.
Existing patients can reorder hCG, bacteriostatic water and syringes through our refill request form. Men’s hormone care is available at our West Hollywood, West Los Angeles, Westlake Village, Valencia, Summerlin / Las Vegas, Paradise Valley / Scottsdale clinics.
hCG on TRT FAQs
How much hCG should I take on TRT?
The usual dose is 500 IU injected under the skin 2-3 times per week. Some men do well on 250 IU. Doses above 500 IU raise estradiol more without clear added benefit for most men on TRT.
How many units is 500 IU of hCG?
It depends on how the vial was mixed. If 5,000 IU is mixed with 5 mL of water (1,000 IU/mL), 500 IU is 0.5 mL, or 50 units on an insulin syringe. If it was mixed to 2,000 IU/mL, 500 IU is 25 units.
How do I mix 5,000 IU of hCG?
A common mix is 5 mL of bacteriostatic water into the 5,000 IU vial, which makes 1,000 IU per mL. Add the water slowly down the side of the vial, swirl gently without shaking, and refrigerate. Use the volume your provider prescribes.
Does hCG on TRT preserve fertility?
Low-dose hCG is the most studied option for maintaining sperm production while on TRT. In one study, 500 IU every other day kept semen parameters stable. It reduces the risk but doesn’t guarantee fertility, so men actively trying to conceive may be advised to stop testosterone.
Is gonadorelin as good as hCG?
For protecting fertility on TRT, hCG has the stronger evidence. Gonadorelin is a short-acting GnRH that the body normally releases in pulses every 1-2 hours, and a few injections a week don’t fully copy that pattern. Gonadorelin can still suit some men, and your provider will walk you through the trade-offs.
Can I inject hCG and testosterone at the same time?
Yes. Many men inject both on the same day, using separate syringes. Don’t mix them in one syringe.
How long is hCG good for after mixing?
Refrigerate it after mixing and use it within the time on the package insert, typically 30-60 days depending on the product. Don’t freeze it.
Does hCG help with weight loss?
No. hCG has not been shown to cause weight loss, and the FDA does not approve it for that use. We prescribe hCG only for hormone and fertility purposes.
References
- Hsieh TC et al. Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy. J Urol, 2013. PubMed
- Mulhall JP et al. Evaluation and Management of Testosterone Deficiency: AUA Guideline, 2018. American Urological Association
- Pregnyl (chorionic gonadotropin for injection) prescribing information. DailyMed
- Novarel (chorionic gonadotropin for injection) prescribing information. DailyMed
- The “Deemed to be a License” Provision of the BPCI Act (biological products transition, March 2020). U.S. Food and Drug Administration
Men’s Hormone Library
TRT Medication Guides
Doses, lab targets and how we prescribe each medication in our men’s hormone program.
