skylaThere is a new IUD on the market called Skyla. It is made by Bayer, the same manufacturers who brought us the Mirena. Like the Mirena it contains the hormone levonorgestrel, although there are a few differences. The main difference the company is touting is the smaller size. Clearly, they manufacturers are targeting nulliparous women with the promise that a smaller size might mean an easier insertion.

I have summed up Skyla and Mirena in this chart so you can compare them side by side:

Skyla Mirena
Number of years 3 5
Size 30X28 mm 32 X 32 mm
Amount of levonorgestrel in drug reservoir 13.5 mg 19.5 mg
Amount of levonorgestrel released/day at start 14 mcg/day 20 mcg/day
Amount of levonorgestrel released/day at the end 5 mcg/day 10 mcg/day
Cost in $US $650.32 $703.05
Pregnancy rate by end of 3 years 0.33/100 woman years 0.31/100 woman years
Expulsion rate at 3 years 4.56% 3.58%
Discontinuation due to abnormal bleeding 4.7% 4.9%

What about pain with insertion? A randomized study was published this month (Obstet Gynecol Nelson et al November, 2013) ) where the women were blinded to which IUD they received (obviously the investigators knew which IUD they were inserted) gives us some more data. Over 2,800 women received a Skyla or Mirena (just over 1,400 in each group) and 96% of insertions (lumping both Skyla and Mirena together) were successful the first time and 65% of women reported their pain as none or mild. This is very reassuring considering 39% of women in this study had never been pregnant. Interestingly, the study did not report pain or ease of insertion specifically for Skyla versus the Mirena, bur rather lumped them together. It seems incredible to me given the data presented in the study that they didn’t have the breakdown by IUD. The study was funded by Bayer so it makes me wonder if there was actually no difference in pain or failed insertion attempts between the two and so they elected not to disclose that information. Sigh.

Abnormal bleeding patterns, breast tenderness, acne, headache, weight gain, pregnancy rates, and serious adverse events were the same between the two groups so there does not seem to be a side effect, efficacy, or safety advantage for Skyla over Mirena. The only statistically significant difference that came out in this study was a slightly higher incidence of ovarian cysts with Mirena over Skyla (13.8% versus 7.7% by 3 years).

The disadvantage to Skyla besides cost? If you are planning on needing contraception for a long time a shorter duration of use increases your risk, as the biggest risk with an IUD is with insertion the longer acting the IUD the safer.

The take away message is that Skyla is a fine contraception, but unless more data is released it seems like there is no real advantage over Mirena for anyone except perhaps for women with a history of recurrent ovarian cysts and of course Bayer as Skyla is more expensive per year of use.

It is no coincidence that Skyla comes at a time when the patent has expired (or is about to expire) on Mirena.

Join the Conversation


  1. “slightly higher incidence of ovarian cysts with Mirena over Skyla (13.8% versus 7.7% by 3 years).”

    I don’t understand this part. That seems like a big increase – doubled incidence??
    Or does it mean the increase on likelihood, like the likelihood was small and that small number increased by 14%. Sorry for the weird questions. Thinking of switching to an iud at my next appointment so I want to know what I’m getting into. Thanks.

    1. While a doubling in the incidence of cysts seems big, it may or may not be and unfortunately the study isn’t powered or really even designed to look at ovarian cysts. For example, if the incidence of ovarian cysts in women who got a copper IUD were 10% that might make the 13.8% meaningless. Also, as the removal rate for complications were essentially identical for the Skyla and the Mirena, so even if there were a true increase in cysts they did not seem to have any health impact.

      Other studies report the incidence of ovarian cysts at about 10% with Mirena, which may or may not be statistically difference from the 7.7% for Skyla. So, without a study designed to specifically look at cysts I think it’s really hard to draw a firm conclusion from this study. For me, the most important thing is the removal rates were the same so even if the true incidence of cysts is higher (which this study wasn’t really designed to tell us), it doesn’t seem to have a clinically significant outcome.

      Hope that helps! And good question, thanks for asking!


  2. The Skyla seems like a strange option. I am on my third Mirena and if they had a ten-year version I would switch to that since insertion really is the worst part. For the next one I’m going to see if I can find out which doctor in the practice has the most experience and see that person, but that will be in 2017.

    I know that copper does last ten years but the benefits of not getting my period are huge for me: no dogs tearing through the bathroom trash, no purchasing feminine products, no cramping, no eating salt from the shaker, no ruined clothes, no surprises at work, no turning down sex ; )

    Whenever I hear about men getting vasectomies for birth control I’m (quietly) horrified that a couple considered that their best choice. It seems a lot more painful, a lot more permanent, and someone still gets their period.

    1. I will happily take my husband down for his and he will happily get it, 12 yrs of me being on hormonal birth control wrecked havoc on our relationship and would have still if I hadn’t got a copper IUD and have resumed my normal levels of crazy. You name it I tried it and it all made me crazy or have abyssal side effects, sometimes a vasectomy is BEST gift a husband can give his wife because my body has been the battleground for our fertility and if with a simple outpatient snip he can show his appreciation of my taking control, the risk and side effects of our war against our fertility for 12 yrs i won’t stop him.

  3. I am really happy with my Skyla. I am really hormone sensitive, the Mirena gave me awful awful headaches. So far three months into Skyla and no headaches! Still getting my period, though.

    1. I also have the Skyla IUD and had it inserted in December 2013. I am starting to freak out—I had a period the month I got it, and then one last month, and now the 3rd month (Feb)–I don’t have it yet! I know it’s only a few days late, but just wanted to see if you had any irregular cycles or months where you had or didn’t have one. Thanks, Christina

      1. I’ve had the Skyla for 3 years, April 2016! I spotted for 5-6 days after insertion, and haven’t had a cycle since! I have endometriosis, so it’s ok for me to not have a cycle, bc I bled for 73 days, straight before getting it! (TMI) sorry! Now I’m worried because it’s expired, I’m 5 months out, and not sure if it still works. It’s going to cost us, $550 to take out, and if I want it again, it’s $1200 to take out, and put in! But I would do it all over again bc I’ve been on 10 different BC pills, and this is the only one that’s stopped my pain, cramps, ect.
        Good luck💙

  4. I’m curious if the Skyla would be better for breast feeding women? Could that be a benefit? I chose Mirena after my Kiddo was born because of breast feeding, because I was told that the levonorgestrel alone was better than the combo pill (yes, I know that the mini pill is an option. But, seriously, with a newborn how is a pill that I have to remember to take at the exact same time every day a good option? I know a copper IUD might be better, but I have awful periods when not on BC.)

    1. I was wondering this too. I wonder why more women don’t have experiences to share about using Skyla while breastfeeding. The lower hormone levels sound like a happy medium b/t Paragard and Mirena.

  5. Dr. Jen, from one physician to another, thank you for the analysis!! When do you have time to do this reseach and writing??!! I do not even practice OB any longer..and I do not think I could find the time..
    I think the difference in the size seems minimal, and probably not significant in terms of successful insertion ( as you pointed out).
    I hope the patent results in a lower cost, but of course this will not translate to any increase
    in the insertion fees to providers, which I think is too low for the risk we take and the preparation in terms of counseling…

  6. Is Skyla safer for breast (against developing breast cancer) as it contains lower dosage of Levonorgestrel compared with Mirena? Thanks, kate.

    1. I’ve been on Skyla for 7 month now and since having my son in November, i can slowly see the weight coming off. I really haven’t had the adverse affects like i had with the pill or the nuva ring (i.e. mood swings, emotions, hunger, etc.) but i have had some spotting on and off. My doctor recommended Skyla instead of Mirena since its cheaper and I don’t plan to be on it more than 2-3 years. I highly recommend.

      1. Actually after reading some comments it did remind me that the spotting and cramping occurs after intimacy. Normally like the day after. I wonder if that’s a cause for concern?

  7. Hey Jen,
    We got a problem and we need to study the performance of Skyla. In our initial search we found that Skyla was first launched in Feb 2013 and then withdrawn from market in 6 months and then again they launched the product in Nov 2013 and continued. As I don’t belong to this field, I could not find more details about the same. Could you please help me to find the reason behind the same and what happened after that. It will be really very helpful. Thanks in advance and thanks for this post.

  8. Hi Jen,

    I’m currently using the Mirena IUD and have had it for 6 months. I’m experiencing significant pain during and after sex (all types of sex), some bleeding after sex, and a lot of cramping. The pain seems to be getting worse. I had the Mirena checked yesterday and everything seems to be in the right place. No cysts.

    Do you think because the Skyla is minutely smaller, it may be less uncomfortable than the Mirena long-term?

    1. Hi Lenora,

      I had Mirena for almost two years, but I had it removed today because of the pain I was experiencing during intercourse. Like you, I also had bleeding after intercourse, but I did not experience any cramping. My doctor recommended that I switch to Skyla because I have a small uterus since I am nulliparous. The small size of my uterus led my doctor to believe that the end-tip of the Mirena might have been poking me during intercourse. You should talk to an OBGYN who is experienced in IUD placement, and ask what s/he recommends for you. Unfortunately, I cannot tell you if switching to Skyla has solved my problem because it was just inserted today.

      I wish you luck if you haven’t resolved your problem already 😀

      1. Let me know if Skyla was better for u please. I’m trying to decide between the two. Thanks!

      2. Great article, really appreciate it. Also super appreciate the: “Don’t pull your own IUD out” post. I was going to, but you did a fantastic job taking the time to explain why not to. Thank you.

        I am having my Skyla removed at Planned Parenthood this Thursday.
        I am 47 years old and have had vaginal births.
        I had it inserted by my now retired OB/Gyn as a treatment for menorrhagia and it worked good enough- periods were regular and medium normal to merely heavy; not crazy heavy.
        However, in the last 6 months I have bleed a bit after sex (and sometimes sex triggers the period to start early) and have had a 16 day (the longest so far) heavy clotting period. There is also cramping, and if I get stressed I will bleed a bit.
        The ultrasound last week revealed that the 2 centimeter fibroids (I did not know I had fibroids 2.5 years ago, I was tested before to check for PCOS which was negative) at the top of my uterus converted to a 4.8 centimeter fibroid and was pushing downwards and through the inner lining……

        “Uterus: The uterus measures 11 x 6 x 9 cm. The myometrium is diffusely inhomogeneous. There is a focal fibroid involving the anterior fundal and superior uterine body measuring 4.8 cm in size. This appears to include the area of 2 separate fibroids
        seen on the previous exam with maximum measurements of 2.2 cm and 2.3 cm previously. This fibroid is intramural in origin but large enough that it effaces the adjoining endometrium.
        Endometrium: The endometrial echo complex measures 5 mm which is within normal limits. The intrauterine device is obscured due to the endometrial encroachment by the fibroid.
        Ovaries: The ovaries are of normal size, shape and configuration. There is no evidence of an adnexal mass on either side.
        Doppler: There is intact color flow to each ovary.
        Cul-de-sec: There is no free fluid identified within the cul-de-sac.”


        My vagina was prolapsing a bit last week and my nurse practitioner who could not find my cervix (no problem in January when I had my last pap done with her) last Monday ordered the ultrasound to find the placement of the IUD. She then told me that the bleeding I was having was not normal. I have heard that everything goes crazy during peri-menopause so I just figured the long bleeding was part of that. I am scheduled to see a good OB/GYN in the middle of July; but, I at least want the device out now, hence Planned Parenthood.

        From the description it almost sounds like the dang fibroid is pac-manning the IUD.

        22 years ago I took low dose ovulation-preventing type birth control pills for about 6 months— at which time my new husband begged me to stop taking them because I was so psycho on them. I had been given natural progesterone cream and natural progesterone pills over the past 15 years to help with the heavy bleeding (which started 16 years ago after the birth of my last kid and at the same time as hypothyroidism kicked in) those too made me weepy and psycho. My retired OB/Gyn told me Skyla would not make me crazy and recommended it over the Mirena because of my history. He cautioned me that it might put me into early menopause; but, I continued to bleed the same as I did before my last kid was born. I will say that Skyla did not seem to affect my mood, I did gain 10 pounds but I lost them last year, and I have had pretty consistent minor face skin issues.
        If I had known that I had small fibroids to start with, I would not have put the IUD in because there is a lot of still active debate about progesterone also contributing to fibroids as does estrogen- especially since the fibroids often grow during progesterone-rich pregnancy.

        Skyla did help with menorrhagia and that was a huge relief; but, because of the fibroids and all the bleeding issues I massively regret having it placed at the moment. It has been 6 very uncomfortable months.

        Great blog.

  9. Now what we need is a smaller non-hormonal IUD. That Paragard was way too big for me (so sad), and hormonal birth control and I do not mix. At all. 😦

  10. Hi Jen,

    I had Skyla placed about a month ago and have gained 15# since. I also have development of acne, breast tenderness and extended periods. I talked to my GYN about all this and she says that acne/ breast tenderness and periods should normalize within 3 months but she absolutely refuses to acknowledge that weight gain is associated with Skyla.

    I live an extremely healthy lifestyle and had been at the same weight all my adult life. It seems strange that I would have a sudden increase in significant weight after Skyla without any other lifestyle changes. What’s your experience with it?


    1. hi! i am on my 3rd mon. with skyla. luckily, i am not getting acne and my period is lighter and shorter. however, i have this weight gained, more on water retention that is so hard to fix. i am already exercising 2 hours almost everyday, compare to 1 hour 3-4 times a week before. and I am also eating less. I am already taking water EX pills to pee those excess water, yet i might only lose 1-2 pound a day and will just gain in back. its really depressing, but hopefully this is just the adjustment period.

  11. Good evening Ma’am, you mentioned in the article that the patent has expired or about to expire on the Mirena. Can you please explain what that means? Will the Mirena no longer be available or unsafe?

    1. The expiration of the patent means that the cost for the product will have to go down, because other manufacturers will be able to produce hormonal IUDs like Mirena, but potentially for a lower cost to consumers/insurance companies. Mirena will not be less safe, and they will continue to offer it.

  12. Are there any studies regarding rates of pregnancy with Skyla in multiparous females. I am an Ob-Gyn physician.I am on call for ER often, & treat a large amount of ruptured ectopic pregnancies. I have had incidental ectopics with IUD’s; part of the 0.31per 100 woman year. Tonight, have a G5P3023, with Skyla, that was placed over a year ago, with a ruptured ectopic, that I am taking to the OR. I know this is incidental, & the pregnancy rate is only slightly higher with the Skyla. It would be interesting to know if multiparous females have a higher rate of pregnancy; due to a number of factors such as larger uterus, with smaller IUD with less progesterone. If the pt is multiparous, should pt have the option of Mirena, and should this information be told to patient, when consenting a patient. A clinic had placed the skyla.

    1. Just wondering if you received any follow up information on this post. I am 40 and have two children (not planning on and do not want more), and just had the mirena removed (it has been 5 years). I was looking into the Skyla because I would like an iud with less hormones. I had some weight gain, acne, and some other side effects with mirena. Nothing major, but I was thinking that the side effects would be minimized with Skyla. If it’s a less effective method however, I would stick with Mirena.

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