NuvaRing Does Not Cause High Iron Levels or Low Ferritin
NuvaRing (etonogestrel/ethinyl estradiol vaginal ring) does not cause hyperferritinemia (high iron levels) or low ferritin; in fact, combined hormonal contraceptives like NuvaRing typically increase both hemoglobin and ferritin levels compared to non-users. 1
Effect on Iron Parameters
Combined hormonal contraceptives, including the vaginal ring, have a beneficial effect on iron status:
Current users of hormonal contraceptive methods generally have higher hemoglobin (3-6 g/L increase) and ferritin levels (2-18 g/L increase) compared to non-contraceptors. 1
In anemic women followed longitudinally, combined oral contraceptives (which share the same mechanism as NuvaRing) produced significant mean increases in hemoglobin at 12 months. 1
The mechanism is reduction in menstrual blood loss, which preserves iron stores rather than depleting them. 1
Clinical Context
The vaginal ring releases 15 μg ethinyl estradiol and 120 μg etonogestrel daily and has comparable efficacy, risks, and benefits as other combined hormonal methods. 2 The most frequently reported adverse events in clinical trials were headache (6.6%), leukorrhea (5.3%), and vaginitis (5.0%), with no clinically relevant changes in blood biochemistry or hematology. 3
Contrast with Copper IUDs
It's critical to distinguish NuvaRing from copper IUDs, which have the opposite effect on iron status:
Copper IUD users have lower ferritin levels (difference of 10 g/L) compared to non-contraceptors due to increased menstrual blood loss. 1
71% of copper IUD users reached iron-deficient ferritin levels by 6 months, whereas oral contraceptive users showed no adverse effect on iron balance. 4
Copper IUD use leads to iron depletion and storage iron depletion (ferritin <12 ng/ml) occurs in 25% of users. 5, 6
Bottom Line
If your patient is using NuvaRing and has abnormal iron parameters (high iron or low ferritin), look for alternative explanations rather than attributing it to the contraceptive. NuvaRing should actually protect against iron deficiency by reducing menstrual blood loss. 1