Here’s what’s different about Slinda, the single-hormone contraceptive just added to the PBS

From May 1, the oral contraceptive Slinda (drospirenone) will be listed on the Pharmaceutical Benefits Scheme (PBS). This means the price will drop for the more than 100,000 Australian women who currently use it – from around $A320 a year to around $94.

It’s the third contraceptive pill the federal government has added to the PBS this year, after Yaz and Yasmine. But these two are combined oral contraceptives – meaning they contain both the hormones oestrogen and progestogen – whereas Slinda is progestogen-only.

So, Slinda is a little bit different – here’s how it works and what it will cost.

What is Slinda and how does it work?

Oral contraceptive pills contain active ingredients based on the female sex hormones oestrogen and progesterone to prevent pregnancy.

Contraceptive pills with both hormones are known as combined-contraceptive pills. Progesterone only pills are often referred to as mini-pills.

The active ingredient in Slinda is a progestogen, which is a synthetic derivative of progesterone, which makes the medication a mini-pill.

Slinda works by stopping ovulation (the ovary doesn’t release an egg) and making the mucus in the cervix thicker so sperm cannot get into the uterus from the vagina.

Both combined contraceptive pills and mini pills effectively prevent pregnancy, but their suitability varies for different women. Mini-pills, including Slinda, can be 99% effective if used perfectly – but with typical day-to-day use, they provide only around 93% protection.

Who will find Slinda useful?

Slinda may be a particularly beneficial alternative for people who can’t use contraceptives containing oestrogen.

This may include women who are older, overweight, or prone to migraines. This is because oestrogen is known to increase the risk of blood clots which lead to deep vein thrombosis – already a higher risk for older and overweight women.

Similarly, combined pills containing oestrogen aren’t appropriate for those who’ve had a baby in the last 21 days or are breastfeeding. Lower levels of oestrogen are needed in a woman’s body post-birth as it stimulates prolactin, the hormone responsible for milk production. Taking an oestrogen-based pill can potentially interfere with that.

Slinda can be taken at any time after childbirth, including while breastfeeding, and generally remains a safer option for people with a history of blood clots or migraines.

Slinda also has advantages over other, older generations of progestogen-based contraceptive pills. Mini-pills such as Microlut and Noriday have no pill-free days, whichs means if a woman misses taking the pill by even a few hours it can increase her chance of becoming pregnant.

The pill-free window for Slinda is 24 hours. This means if you are less than 24 hours late it’s considered a late pill, not a missed pill. If you take the late pill as soon as you remember, and then the next pill at the normal time, you should have effective protection from unwanted pregnancy.

What are the risks or potential side effects?

The potential side effects for Slinda are similar to other contraceptive pills. Women may find that their period may stop altogether, or they may experience bleeding irregularities or spotting, as well as breast tenderness.

It is not currently recommended for those with breast cancer, unexplained vaginal bleeding, or severe liver disease, in line with recommendations for all mini-pills.

The pill may also not work effectively if it’s not taken correctly every day, or if it is taken with other drugs, such as the anti-viral ritonavir and anti-seizure medication phenytoin.

If a woman is suffering from vomiting or severe diarrhoea, Slinda may not be effective and she should use back-up contraception such as condoms.

There are other progesterone-only contraceptive options available on the PBS, such as levonorgestrel pills and implants, including the intrauterine devices, Mirena and Kyleena.

Why was Slinda added to the PBS?

Slinda has been available in Australia since at least 2004, but not at a subsidised price.

In November 2024, the Pharmaceutical Benefits Advisory Committee recommended Slinda’s listing on the PBS. The committee cited several reasons, including advice from doctors, the need to provide women with more contraceptive options and Slinda’s longer pill-free window.

At a stakeholder meeting in October 2024, doctors stressed the need for more choice for women, when choosing a pill.

They highlighted women starting an oral contraceptive pill for the first time will often first use PBS-subsidised medications, even though a non-PBS product may be more suitable for them. Slinda’s listing makes it a more accessible first choice for women.

As Slinda is a prescription-only medication, if you wish to change pills or start on the drug you will need to consult your doctor. If you do change, from May 1 and based on similar PBS medications, you can expect to pay around $31 for a four-month supply.