Novarel and Pregnyl are both brand names for the same active drug: human chorionic gonadotropin (hCG), extracted from the urine of pregnant women and purified for injection. They share the same FDA-approved uses, the same dosing, and the same route of administration. The differences between them come down to manufacturer, inactive ingredients, and how long they last after mixing.
Same Drug, Different Manufacturers
Novarel is made by Ferring Pharmaceuticals, while Pregnyl is manufactured by Merck Sharp & Dohme. Both products contain hCG as a freeze-dried powder that you reconstitute with a liquid diluent before injection. Both are given as intramuscular shots, typically administered by a healthcare professional.
The FDA-approved indications are identical for both brands:
- Ovulation induction in women undergoing fertility treatment whose inability to ovulate is not caused by primary ovarian failure
- Hypogonadotropic hypogonadism in males, a condition where the pituitary gland doesn’t signal the testes to produce testosterone
- Prepubertal cryptorchidism (undescended testicles) in boys, typically between ages 4 and 9, when the cause isn’t a physical blockage
If your fertility clinic or pharmacy switches you from one to the other, the therapeutic effect is the same. Both deliver hCG at the same potency measured in USP Units.
Minor Differences in Formulation
Pregnyl’s powder contains monobasic sodium phosphate (5 mg) and dibasic sodium phosphate (4.4 mg) as buffering agents. Its diluent is sterile water with 0.56% sodium chloride and 0.9% benzyl alcohol as a preservative. This means Pregnyl is not safe for use in newborns, since benzyl alcohol can be toxic to them.
Novarel uses a slightly different formulation. While the active ingredient and overall purpose of the excipients are comparable, the specific inactive ingredients and preservative system differ enough that the two products are not perfectly interchangeable from a formulation standpoint, even though clinically they work the same way. If you have a known allergy to benzyl alcohol or any specific buffer, check the label of whichever brand you’re prescribed.
Storage After Reconstitution
This is the most practical difference between the two brands. Once mixed with diluent, Novarel stays stable in the refrigerator (36 to 46°F) for up to 30 days. Pregnyl lasts twice as long: up to 60 days refrigerated after reconstitution. Neither should be frozen.
Before mixing, both products are stored at room temperature as dry powder. The difference in post-reconstitution shelf life matters most if you’re on a multi-dose regimen. With Novarel, you have a tighter window to use the vial once it’s been prepared. If your treatment plan spans more than a month, Pregnyl’s longer stability could mean less wasted medication.
Why Your Pharmacy Might Substitute One for the Other
Because both products contain the same active ingredient at the same strength, pharmacies sometimes dispense whichever is in stock or covered by your insurance. Pricing can vary between the two, and insurance formularies may prefer one brand. If your prescription says “Pregnyl” but you receive Novarel (or vice versa), you’re getting the same hormone at the same dose.
The one thing worth confirming with your pharmacist is whether the inactive ingredients differ in a way that matters for you personally, particularly if you have preservative sensitivities. Beyond that, switching between the two brands does not require a dosage adjustment or a change in your treatment protocol.
What hCG Actually Does in Treatment
In fertility treatment, hCG mimics the natural hormonal surge that triggers ovulation. It’s typically given as a single injection (often called a “trigger shot”) after follicles have been stimulated with other hormones. The timing of this shot is critical, usually 24 to 36 hours before egg retrieval or timed intercourse.
In males with hypogonadotropic hypogonadism, hCG stimulates the testes to produce testosterone, essentially standing in for the signal the pituitary gland isn’t sending. Treatment can continue for weeks or months depending on the goal, whether that’s raising testosterone levels, improving fertility, or both.
For boys with undescended testicles, hCG can sometimes encourage the testes to move into the scrotum. This response is temporary in most cases, and surgery may still be needed later. The treatment is typically used as a way to assess whether the testicle is capable of descending on its own.
One important note that appears in bold on both labels: hCG has not been shown to be effective for weight loss. Despite its popularity in some diet programs, there is no substantial evidence that it increases weight loss beyond what calorie restriction alone achieves, changes fat distribution, or reduces hunger.