What’s the real difference between Mirena vs Kyleena vs Skyla—like who is each one actually best for, and how long do they last without me having to think about it?

Here’s the short version: all three are hormonal IUDs with levonorgestrel (a progestin), but they differ in size, hormone dose, and how long they last.- Mirena: highest dose (52 mg), lasts up to 8 years for birth control. Best if you want longest protection, have heavy periods, or love the idea of possibly no period at all.- Kyleena: middle dose (19.5 mg), lasts 5 years. Smaller than Mirena, solid option if you want long-term birth control but are nervous about hormones or side effects.- Skyla: lowest dose (13.5 mg), lasts 3 years. Smallest device, often used for first-timers or anyone wanting a shorter commitment.All three are over 99% effective at preventing pregnancy.If you want to sanity-check which IUD actually fits your life (and your uterus), you can talk it out with Gush and unpack your cycle, symptoms, and worries without being rushed.

Mirena vs Kyleena vs Skyla: how they differ, who they’re for, and how long they last

First, the hormonal IUD basics

Hormonal IUDs are T-shaped devices that sit in your uterus and slowly release levonorgestrel (a synthetic version of progesterone). They prevent pregnancy by:- Thickening cervical mucus so sperm basically hit a brick wall.- Thinning the uterine lining so even if an egg is around, implantation is unlikely.- In some people, especially with Mirena, partially blocking ovulation.Effectiveness: all three are over 99% effective. Translation: they beat the pill, condoms, and pulling out by a mile.Your natural menstrual cycle usually goes:- Follicular phase: estrogen rises, uterine lining builds.- Ovulation: LH surge, egg released.- Luteal phase: progesterone rises, body acts like it might be pregnant.- Period: hormones drop, lining sheds.With a hormonal IUD, your ovaries often keep cycling (especially with Kyleena and Skyla), but the uterine lining is so thin and the cervical mucus so hostile that pregnancy is extremely unlikely.

Mirena: longest-lasting and strongest for heavy periods

Key stats:- Hormone dose: 52 mg levonorgestrel.- Duration: FDA-approved for up to 8 years for contraception.- Size: standard IUD size.Who Mirena is usually best for:- You want true set-it-and-forget-it for most of your 20s.- You have heavy, painful periods and are sick of bleeding through everything.- You’re open to your period getting very light or possibly disappearing.Mirena dumps a bit more hormone locally into your uterus, which means:- More powerful thinning of the uterine lining over time.- Higher chance of lighter periods or no bleeding at all.- Often fewer cramps and less period-related anemia.Cycle-wise, many people with Mirena still ovulate, but the luteal-phase action in the uterus is basically muted. Your ovaries may go through the normal estrogen-then-progesterone rhythm, but the lining barely responds, so bleeding is minimal.

Kyleena: the middle-ground, 5-year option

Key stats:- Hormone dose: 19.5 mg.- Duration: up to 5 years.- Size: slightly smaller than Mirena.Who Kyleena is usually best for:- You want long-term birth control but feel nervous about the highest-dose IUD.- You’ve never been pregnant and your provider wants a smaller device.- You like the idea of some period-lightening but don’t necessarily want it to vanish.Kyleena’s lower dose often means:- Your periods get lighter and less crampy, but not always fully gone.- Your natural cycle tends to keep running more obviously – you might still feel ovulation twinges or PMS.Because the hormonal impact on the ovaries is weaker than Mirena, ovulation is more likely to continue regularly. The main game is still local: mucus and lining.If all this still feels like alphabet soup and vibes, this is exactly the kind of thing you can sort through with Gush – real talk about your bleeding, pain, mood, and what actually sounds livable for you.

Skyla: smallest size, lowest dose, shortest commitment

Key stats:- Hormone dose: 13.5 mg.- Duration: up to 3 years.- Size: the smallest of the three.Who Skyla is usually best for:- You’re new to IUDs and want a shorter trial period.- You or your provider are worried about insertion pain or a very small uterus.- You don’t need 5–8 years of birth control right now.Skyla is lighter on the hormonal punch, which often means:- Periods usually get lighter but often stay monthly.- Spotting and irregular bleeding in the first 3–6 months (common with all three), then things tend to settle.Because Skyla’s dose is lower, it does less to blunt ovulation. Your hormonal cycle (follicular, ovulation, luteal) is more likely to stay intact, but the uterine environment is still hostile to pregnancy.

How each IUD changes your period and the phases of your cycle

First 3–6 months with any hormonal IUD:- Irregular spotting is extremely common.- Your body is adjusting to continuous progestin hitting the uterine lining.Over time:- Mirena: highest chance of minimal or no bleeding. Your follicular and luteal hormones may still rise and fall, but the endometrium often stays thin. PMS may or may not improve – some people feel less mood fluctuation, some feel no change.- Kyleena: moderate bleed reduction. You may still see obvious cycle phases – egg-white discharge before ovulation, luteal-phase sore boobs, then a lighter bleed.- Skyla: mild-to-moderate reduction. Cycles often look the most traditional, just less intense.Irregular cycles or PCOS?- A hormonal IUD won’t magically regulate ovulation like the pill can, but it can control bleeding and cramps.- If you’re used to chaotic periods, Mirena can cut down bleeding even if ovulation is irregular beneath it.

Side effects, vibes, and who each one is actually ‘for’

Possible side effects shared by all three:- Cramping after insertion (usually days to weeks).- Spotting for months.- Hormone-related effects in some people: acne, breast tenderness, mood shifts, headaches.Because Mirena has a higher dose, any hormone-y side effects (if they show up) may be more noticeable, but this is wildly individual. Plenty of people have zero issues on Mirena and more issues on something like Nexplanon or the pill.Rough matching guide:- Mirena: you want max effectiveness, longest duration, heavy-period relief, and are ok with possible no-period life.- Kyleena: you want medium hormone, medium duration, smaller size, and a shot at keeping a lighter, still-somewhat-regular period.- Skyla: you’re testing the IUD waters, want less hormone and shortest commitment, or need the smallest device.The real answer to who each is best for: the one that fits your pain tolerance, bleeding pattern, anxiety level about hormones, and life plans. You’re not picking a forever partner; you’re picking a 3–8 year teammate you can absolutely fire if it doesn’t treat you right.