Short answer: Both are hCG given one day after the last dose of follicle-stimulating medicine to trigger ovulation.12 Ovidrel is recombinant hCG, a single 250 µg shot under the skin, also used in IVF. Novarel comes from pregnancy urine, is injected into a muscle at 5,000 to 10,000 USP units, and is also approved for undescended testicles in boys and some men with low testosterone. Neither has a boxed warning.
| Ovidrel | Novarel | |
|---|---|---|
| What it is | Choriogonadotropin alfa, recombinant hCG1 | Chorionic gonadotropin from human pregnancy urine2 |
| Approved for | Final egg maturation in IVF and other assisted reproduction; ovulation induction in anovulatory women1 | Ovulation induction after menotropins; undescended testicles in boys; some men with hypogonadotropic hypogonadism2 |
| Trigger dose | 250 µg one day after the last dose of the follicle-stimulating agent1 | 5,000 to 10,000 USP units one day after the last dose of menotropins2 |
| How given | Under the skin; single-dose prefilled syringe that may be self-injected1 | Into a muscle only; 5,000 or 10,000 unit multiple-dose vials mixed with bacteriostatic water containing benzyl alcohol2 |
| Side effects | IVF studies: any event 33.1%, injection site reactions 14.0%, abdominal pain 4.2%, nausea 3.4%1 | No percentages: headache, irritability, restlessness, depression, fatigue, swelling, injection site pain2 |
| Ovarian hyperstimulation (OHSS) | 1.7% in IVF trials, 3.0% in the ovulation induction trial1 | Listed as a principal serious reaction with menotropins; no rate given2 |
| Boxed warning | None1 | None2 |
Yes, but not with Novarel by name. The Ovidrel label reports three trials against "an approved urinary-derived hCG product" at 5,000 or 10,000 units. In IVF the number of eggs retrieved, and in ovulation induction the ovulation rate, were found to be clinically and statistically equivalent. Across four studies, injection site problems were 14.6% on Ovidrel 250 µg vs 28% on the urine-derived hCG, and a small liver enzyme (ALT) rise was 3% vs 4.8%.1
Both warn about ovarian hyperstimulation syndrome, ovarian enlargement or cysts, multiple births and arterial blood clots, and both say hCG can affect LH blood tests.12 Ovidrel is not given that cycle if the ovaries are abnormally enlarged on the last day of FSH, and women are followed for at least two weeks after it.1 The Novarel label adds warnings for its other uses: early puberty in boys treated for undescended testicles, fluid retention, and a gasping syndrome in premature infants linked to benzyl alcohol in the diluent.2 The Novarel label also states hCG has not been shown to be effective for treating obesity.2
Which, if either, fits is for your prescriber. More detail: Ovidrel side effects, Novarel side effects, the Ovidrel and Novarel dosing schedules, the hCG missed-dose page, Ovidrel vs Pregnyl: how do recombinant and urinary hCG differ? and Gonadorelin vs hCG: how do they differ?.