Who this guide is for
This guide is for men using HCG, either alone to support their own testosterone production or alongside testosterone therapy to help preserve testicular function and fertility. It assumes you have already been shown how to mix and inject in person, and want a clear reference for doing it at home.
HCG today comes as an FDA-approved product such as Pregnyl. Since 2020 it has been regulated as a biologic, which ended compounded HCG; our article on why compounded HCG disappeared explains the change. Pregnyl arrives as a freeze-dried powder that has to be mixed before use, and that mixing step is where most questions come from.
What is in the box, and which liquid to use
The Pregnyl label describes a powder vial containing 10,000 USP units of chorionic gonadotropin, packaged with a 10 mL vial of solvent. That solvent is water for injection with 0.56% sodium chloride and 0.9% benzyl alcohol as a preservative, which makes it a bacteriostatic diluent: it slows bacterial growth so the vial can be entered for dose after dose.
Some pharmacies dispense bacteriostatic water instead. The bacteriostatic water label describes sterile water with 0.9% benzyl alcohol, and warns that it is not for use in newborns. Either way, use the liquid your pharmacy supplied or your provider named, never tap water or plain saline from another source. Our page on bacteriostatic water explains the difference between diluents.
The label allows 1 to 10 mL of solvent to be added. How much you add sets the strength of every dose, so that number comes from your provider or pharmacy label, not from a forum.
Mixing, step by step
- Wash your hands and set out the powder vial, the diluent vial, an alcohol swab for each stopper, a mixing syringe and a sharps container.
- Check both vials. The powder should be a dry white cake; the liquid should be clear. Note the expiry dates.
- Flip off the caps and swab both rubber stoppers. Let them air dry.
- Draw the diluent. Pull air into the syringe equal to the volume you need, push it into the diluent vial, turn the vial upside down and draw the exact volume your plan specifies.
- Add it slowly down the glass wall of the powder vial rather than straight onto the cake. Fast spraying can foam the solution.
- Swirl or roll gently until the powder dissolves completely. The label says to agitate gently and not to shake.
- Look at it. The mixed solution should be clear and free of particles. If it is cloudy or has specks, do not use it.
- Write the mixing date on the vial or a strip of tape, and the discard date 60 days later.
- Refrigerate it right away.
Converting IU to insulin-syringe units
This is the part that confuses almost everyone, because two different “units” are involved. HCG doses are measured in international units (IU or USP units) of hormone. Insulin syringes are marked in their own units, which are simply volume: on a standard U-100 insulin syringe, 100 marks equal 1 mL, so each mark is 0.01 mL.
To turn a dose in IU into syringe marks, you need the strength of your mixed vial:
| Diluent added to a 10,000-unit vial | HCG per mL | HCG per insulin-syringe mark (0.01 mL) |
|---|---|---|
| 10 mL | 1,000 units | 10 units |
| 5 mL | 2,000 units | 20 units |
| 2 mL | 5,000 units | 50 units |
| 1 mL | 10,000 units | 100 units |
So the math is: dose in IU divided by HCG units per mark equals the number of marks to draw. The dose itself, and how often you take it, are set by your provider from your labs and goals. The label’s own regimens for men with low pituitary signaling run from hundreds to thousands of units several times a week, which is exactly why this is never a do-it-yourself decision. If the numbers on your syringe ever do not match what you expected, stop and call before injecting.
Habits that prevent conversion mistakes
- Write the strength on the vial when you mix it, for example “1 mark = 10 units”, so nobody has to redo the math at 6 a.m.
- Keep a card in the fridge with your dose in units and the matching number of marks, copied from your written plan.
- Recheck whenever something changes. A different diluent volume, a vial of a different strength or a switch of pharmacy all change the table above.
- Use the same syringe type every time. A 0.3 mL or 0.5 mL insulin syringe has wider spacing between marks than a 1 mL syringe, which makes small doses easier to read, but each numbered unit still equals 0.01 mL on a U-100 syringe.
- Watch the calendar as well as the volume. If a vial runs out noticeably sooner or later than your plan predicts, the dose being drawn may not be the one intended; call before the next shot.
Storing a mixed vial
| Stage | What the Pregnyl label says |
|---|---|
| Before mixing | Store at controlled room temperature, 59°F to 77°F (15°C to 25°C) |
| After mixing | Refrigerate at 36°F to 46°F (2°C to 8°C) |
| Usable for | Discard 60 days after mixing |
| Never | Freeze it |
Keep the vial in the main body of the fridge rather than the door, where temperatures swing, and away from the back wall, where things can freeze. For travel, a small insulated pouch with a cold pack works for a day; do not let the pack touch the vial directly. Our guide on storing peptides and injectables covers fridge setups and travel in more detail.
Injecting HCG, and what to watch for
The Pregnyl label lists intramuscular use. Many treatment plans use a small subcutaneous injection with an insulin syringe instead, which is off-label; your provider tells you which route is yours and why. For under-the-skin shots, MedlinePlus describes pinching about an inch of skin and fat on the belly or thigh, inserting at 90 degrees, or 45 if you are lean, and moving each injection at least an inch from the last. Our subcutaneous injection guide walks through the same technique in more detail.
HCG and testosterone are never combined in one syringe; our page on mixing HCG and testosterone together explains why, and the one on HCG timing with TRT covers scheduling.
Call the clinic at 626-319-5261 for breast tenderness or swelling, new ankle swelling, headaches that keep returning, mood changes, or redness and warmth at an injection site that spreads.
Call 911 for swelling of the face, lips or throat, hives with trouble breathing, chest pain, or sudden one-sided weakness or slurred speech.
How Ultimate Male supports HCG at home
At our San Gabriel and Downey clinics, HCG starts with labs and a one-on-one consultation with a PA-C or MD, whether you are using it on its own or with testosterone. If it fits, a clinician mixes the first vial with you, shows you how to read the syringe for your dose, and gives you the first injection with you watching or doing it yourself.
Follow-up labs confirm the dose is doing its job; our page on lab monitoring on HCG explains which markers are checked. To learn how HCG fits into a TRT plan, see HCG with testosterone therapy, then book a visit to talk through your testosterone therapy options.
