Yes, Kyleena is smaller than Mirena
Kyleena measures 28 mm by 30 mm and weighs 19 mg (with 19.5 mg levonorgestrel released over 5 years). Mirena is larger at 32 mm by 32 mm and weighs 52 mg (with 52 mg levonorgestrel released over 8 years). Both are T-shaped IUDs, but Kyleena's smaller size suits women with smaller uteruses or those new to IUDs.[1][2]
How do insertion and removal differ?
Kyleena uses a thinner 3.8 mm inserter (vs. Mirena's 4.4 mm), easing insertion, especially for nulliparous women. Removal is similar for both, involving string pull.[1][3]
Which suits smaller uteruses better?
Kyleena fits better in smaller cavities (e.g., under 7-10 cm depth), reducing cramping or expulsion risk. Mirena may cause more discomfort in such cases but offers longer protection.[2][4]
Kyleena vs. Mirena: Hormone dose and effectiveness
Kyleena releases less hormone (17.5 mcg/day initially, dropping to 7.4 mcg/day) but matches Mirena's 99%+ pregnancy prevention and heavy bleeding reduction. Mirena (20 mcg/day initially) excels more at bleeding control.[1][5]
Cost and availability
Both cost $800-$1,200 uninsured in the US; insurance often covers fully. Kyleena lasts 5 years; Mirena 8. Generic options are limited.[6]
Side effects patients report most
Common to both: cramping, spotting, acne (milder with Kyleena's lower dose). Expulsion risk is 4-5% in year 1, higher with smaller IUDs like Kyleena in very small uteruses.[3][4]
[1]: FDA Label - Kyleena
[2]: FDA Label - Mirena
[3]: ACOG IUD Guidelines
[4]: Planned Parenthood Comparison
[5]: NEJM Study on Levonorgestrel IUDs
[6]: GoodRx Pricing