What is the Chelsea 35 pill?
The Chelsea 35 pill, officially branded as CHELSEA-35 ED in some regions, is a combined oral hormonal medication. The pill combines two active ingredients: the progestin and antiandrogen cyproterone acetate and the estrogen ethinyloestradiol. The '35' in the name refers to the 35 micrograms of ethinyloestradiol in each active tablet. The 'ED' indicates an 'every day' pack, which typically contains 21 active tablets and 7 inactive placebo tablets.
This medication is specifically used for the treatment of androgen-dependent conditions in women and also serves as a highly effective oral contraceptive. Androgens are a group of male sex hormones that are also present in women, and an oversensitivity or overproduction of these hormones can lead to conditions like excessive hair growth and persistent acne.
How does the Chelsea 35 pill work?
The dual hormone formulation of the Chelsea 35 pill works on several fronts to address its targeted conditions. The ethinyloestradiol acts as an estrogen, while the cyproterone acetate functions as both a progestin and a potent antiandrogen.
Contraceptive Action:
- Suppresses Ovulation: The combination of hormones prevents the ovaries from releasing an egg each month, which is the primary mechanism for preventing pregnancy.
- Thickens Cervical Mucus: The hormones cause the cervical mucus to thicken, creating a physical barrier that makes it more difficult for sperm to travel through the cervix to reach an egg.
- Alters Uterine Lining: The pill also alters the lining of the uterus, making it less receptive to a fertilized egg.
Antiandrogen Action:
- Blocks Androgen Receptors: The cyproterone acetate specifically blocks the effects of androgens by interfering with their receptors in the body.
- Reduces Androgen Production: The antigonadotropic effect of the combined hormones also helps suppress the ovaries' production of androgens, further reducing their impact.
Administration
CHELSEA-35 ED is taken as part of a cycle.
- A typical pack contains active tablets and placebo tablets.
- One tablet is taken at the same time each day.
- Follow the instructions provided with the medication regarding the order and type of tablets to take each day.
- A withdrawal bleed (a period-like bleed) usually occurs during the phase when inactive tablets are taken.
- A new pack should be started according to the prescribed schedule, without a break.
- Forgetting an active tablet can reduce its contraceptive effectiveness and requires following specific instructions. Forgetting a placebo tablet does not affect contraceptive protection.
Benefits beyond contraception
Beyond its contraceptive purpose, the Chelsea 35 pill offers several therapeutic benefits for women, including:
- Treats Severe Acne: It effectively manages severe acne that has not responded to other treatments by regulating the hormonal imbalances that cause it.
- Reduces Hirsutism: It decreases mild to moderate excessive facial or body hair growth by blocking androgen effects.
- Decreases Period Pain: Many users experience a reduction in menstrual cramps.
- Reduces Menstrual Blood Loss: It can lead to a decrease in the amount of blood lost during each cycle, which can also help prevent anaemia.
- Protects Against Certain Cancers: Studies suggest a reduced risk of developing cancer of the uterus lining and ovaries.
- Decreased Risk of Ovarian Cysts: Oral contraceptives can reduce the likelihood of developing ovarian cysts.
Important risks and side effects
Like all medications, the Chelsea 35 pill carries risks and potential side effects. The most serious risk is the increased likelihood of blood clots (thrombosis), which can occur in the legs, lungs, or other parts of the body. The risk is particularly high during the first year of use and is further increased by factors such as age (especially over 35), smoking, and obesity.
Common side effects include:
- Nausea and bloating
- Headaches or migraines
- Breast tenderness or swelling
- Changes in mood and sex drive
- Breakthrough bleeding or spotting, particularly during the first few months
- Changes in body weight
Serious side effects requiring immediate medical attention include:
- Severe pain in the chest, legs, or abdomen
- Sudden shortness of breath or persistent coughing
- Sudden loss of vision
- Severe, unusual headaches or migraines
- Weakness or numbness on one side of the body
- Yellowing of the skin or eyes (jaundice), indicating liver problems
Comparison with other birth control methods
Chelsea 35, containing an antiandrogenic progestin, differs from standard and newer oral contraceptives. The following table provides a comparison to illustrate the differences.
| Feature | Chelsea 35 (Cyproterone Acetate/EE 35) | Standard Combined Pill (e.g., Norgestimate/EE) | Progestin-Only Pill ('Minipill') |
|---|---|---|---|
| Hormones | Estrogen (EE) + Progestin (CPA), high antiandrogen effect | Estrogen (EE) + Progestin, varying types and doses | Progestin only (e.g., norethindrone) |
| Primary Use | Severe acne, hirsutism, and contraception | Contraception, some acne improvement | Contraception (esp. for estrogen sensitivity) |
| Effectiveness | High for contraception and androgen-dependent issues | High for contraception | High, but timing is critical |
| VTE Risk | Increased risk compared to other combined pills | Standard increased risk for combined pills | No increased VTE risk related to estrogen |
| Regimen | Typically involves a cycle of active and placebo tablets | Typically 21 active / 7 placebo, or extended cycle | 28 active tablets, no placebo break |
| Patient Profile | Women needing hormonal treatment for severe androgen symptoms | General contraceptive use | Women who cannot take estrogen (e.g., breastfeeding, high BP) |
Important considerations and conclusion
As of February 2020, the brand CHELSEA-35 ED was cancelled in Australia. This highlights the potential for brand availability changes in different countries. Given the specific risks and indications, this medication should only be taken under the strict guidance of a healthcare provider. Before starting Chelsea 35, a comprehensive health assessment, including personal and family medical history, is crucial to determine if the benefits outweigh the risks. Women over 35 who smoke should particularly avoid this medication due to a significantly higher risk of cardiovascular events. Alternatives with lower risk profiles may be more suitable for women seeking contraception alone.
In conclusion, the Chelsea 35 pill is a specialized medication with a dual function. While effective for treating severe acne and hirsutism, and providing contraception, its use requires careful medical evaluation due to serious side effects like increased blood clot risk. Anyone considering this medication should discuss all risks and benefits with their doctor and inquire about current brand availability and safer alternatives. You can find more information on medication safety and usage on reputable health sites like NPS MedicineWise.
