Mirena & Copper Coils:
Your Questions Answered

Whether you’re considering long-term contraception for the first time or looking to move away from the pill, an intrauterine device may be one of the most effective and liberating options available to you.

As a GP with a special interest in women’s health, coil fitting is one of the procedures I find most rewarding. When it’s done right, in the right environment, with proper preparation and genuine follow-up, it can truly transform a woman’s relationship with her own health. Let me take you through everything you need to know about the two most popular options: the Mirena (hormonal IUS) and the copper IUD.

What Is a Coil?

A coil is a small, T-shaped device inserted into the uterus through the cervix. It is one of the most reliable forms of reversible contraception available, with failure rates of less than 1% for both types. Once fitted, it requires no daily action — a genuine “fit and forget” method for most women.

There are two distinct types, and the right choice depends on your health history, cycle, symptoms and personal priorities — something I discuss carefully with every patient before we decide together.

Who Is a Good Candidate?

Both types of coil are suitable for the vast majority of women, including those who have not had children. The idea that IUDs are “only for women who have completed their families” is an outdated misconception I am always glad to dispel.

The Mirena may suit you if you…

Experience heavy, painful or irregular periods; have endometriosis or adenomyosis; are approaching perimenopause and need contraception alongside HRT; or simply prefer lighter or absent periods.

The copper coil may suit you if you…

Prefer a completely hormone-free option; have experienced mood changes or migraines on hormonal methods; are breastfeeding; or have had a history of hormone-sensitive conditions.

Why Choose a Private Fitting?

Many women ask me this directly. The NHS provides excellent services, and I would never diminish the care available there. However, waiting times, brief appointments and varying specialist experience mean that for many women, a private fitting offers something genuinely different.

What to Expect at Your Appointment

Fitting by a Doctor — Why It Matters

In many settings, coil fittings are carried out by nurses or healthcare practitioners — and many are highly skilled. However, there are specific advantages to a doctor-led fitting, particularly when your health picture is more complex.

If anything unexpected arises during the procedure — anatomical variation, unusual pain, a clinical finding — it can be addressed immediately, by the same person performing the insertion. I can prescribe in the moment, discuss findings in real time and integrate everything into your wider care. For women with endometriosis, adenomyosis, fibroids, a history of pelvic inflammatory disease, or previous difficult fittings, this clinical oversight can make a significant difference to both the experience and the outcome.

The Mirena: More Than Contraception

The Mirena IUS is licensed for several conditions beyond contraception. For women with heavy menstrual bleeding, it is a first-line treatment option — often more effective than oral medication, reducing blood loss by up to 90%. For many women, periods stop altogether within the first year.

In perimenopause, the Mirena provides the progestogen component of menopausal hormone therapy, removing the need for a separate oral or topical progestogen. Emerging evidence also supports its role in endometriosis-associated pain, offering a local hormonal effect with minimal systemic exposure.

Removal & Reversibility

Both devices can be removed at any time. The procedure takes only a minute or two. Fertility returns quickly — immediately with the copper coil, and within one to three months for most Mirena users. Neither device poses any long-term risk to fertility, which is one reason it is increasingly the preferred choice for women who want flexibility as well as reliability.

Common Questions

Can I have a coil if I haven’t had children?

Yes. While the cervix may be slightly narrower, fitting is performed routinely in nulliparous women. I use appropriate technique and take additional time where needed to ensure your comfort.

When does it start working?

The copper coil is effective immediately. The Mirena is effective immediately if fitted in the first seven days of your cycle; otherwise, use additional contraception for the first seven days.

Will I feel it during daily life or sex?

You should not feel the device itself. The fine threads that hang through the cervix are occasionally noticeable — if this is a concern, trimming the threads at a follow-up is a simple solution.

What if the fitting is unsuccessful?

On rare occasions, a first attempt is not possible due to cervical spasm or anatomical factors. I will discuss all options with you — including cervical softening agents or referral for fitting under sedation if appropriate. You will never be sent away without a plan.