Larissia is a combination birth control pill containing two synthetic hormones: a progestin called levonorgestrel (0.15 mg) and an estrogen called ethinyl estradiol (0.03 mg). It comes in a 28-day pack with 21 active hormone tablets and 7 inactive placebo tablets. Larissia is a generic version of brand-name pills like Nordette and works the same way as other combination oral contraceptives in its class.
How Larissia Prevents Pregnancy
The two hormones in Larissia work together primarily by stopping ovulation, meaning your ovaries don’t release an egg each month. Without an egg available, sperm has nothing to fertilize. The hormones also thicken cervical mucus, making it harder for sperm to reach the uterus, and thin the uterine lining, which makes implantation less likely if an egg were somehow released and fertilized.
With perfect use, combination pills like Larissia are over 99% effective. In real-world typical use, where people occasionally miss pills or take them at inconsistent times, the failure rate is closer to 5 to 9 pregnancies per 100 women per year. The gap between those numbers comes down almost entirely to human error, not the medication itself.
How to Take It
You take one pill daily for 28 days, ideally at the same time each day. The first 21 pills contain hormones. The last 7 are placebo pills that contain no active ingredients. Your period typically arrives during this placebo week.
If you start Larissia within the first five days of your period, you’re protected right away. If you start at any other point in your cycle, use a backup method like condoms for the first seven days of active pills.
What to Do If You Miss a Pill
Missing one pill (up to 48 hours late) is relatively low-risk. Take the missed pill as soon as you remember, even if that means taking two pills in one day. No backup contraception is needed.
Missing two or more consecutive pills is a different situation. Take the most recent missed pill right away and discard any other missed pills. Continue taking the rest of the pack on schedule, but use condoms or abstain from sex until you’ve taken active pills for seven consecutive days. If those missed pills fell in the last week of your active pills (roughly days 15 through 21), skip the placebo week entirely and start a new pack immediately after your last active pill. This prevents a gap in hormone levels that could allow ovulation.
If you missed pills during the first week and had unprotected sex in the previous five days, emergency contraception is worth considering.
Common Side Effects
The most frequently reported side effects are nausea, headache, breast tenderness, bloating, ankle swelling from fluid retention, and weight changes. Spotting or irregular bleeding between periods is also common, particularly during the first two to three months as your body adjusts. These side effects often diminish after the initial adjustment period.
Larissia can raise blood pressure slightly. More serious but less common side effects include breast lumps, mood changes (including new or worsening depression), severe abdominal pain, dark urine, and yellowing of the skin or eyes. These warrant prompt medical attention.
Blood Clot Risk
All combination birth control pills carry a small but real risk of blood clots, which can lead to deep vein thrombosis, pulmonary embolism, heart attack, or stroke. The risk is low for most women but increases significantly if you smoke and are over 35. That combination is a hard contraindication, meaning Larissia is generally not prescribed in that scenario. Other factors that raise clot risk include a personal or family history of blood clots, prolonged immobility (such as after surgery or during long flights), obesity, and certain inherited clotting disorders.
Medications That Reduce Effectiveness
Certain drugs speed up how your liver processes levonorgestrel, which can lower the hormone levels in your blood enough to reduce contraceptive protection. The main categories include:
- Seizure medications such as phenytoin, carbamazepine, and barbiturates
- Tuberculosis drugs such as rifampin and rifabutin
- Some HIV medications such as ritonavir and efavirenz
- Certain antifungal drugs such as griseofulvin
- St. John’s wort, a common herbal supplement used for mood support
If you take any of these, your prescriber may recommend a different contraceptive method or an additional backup. St. John’s wort is particularly worth knowing about because it’s available over the counter and people often don’t think to mention supplements when discussing their medications.