The Lo Loestrin Fe birth control pack is designed to prevent pregnancy through a regimen of daily oral tablets. While the pack contains different colors of pills, not all are active in preventing pregnancy. The different pill colors serve specific purposes to manage the contraceptive cycle and maintain a daily habit.
The composition of Lo Loestrin Fe
A standard 28-day blister pack of Lo Loestrin Fe contains three distinct types of tablets, each with a different color and composition.
- 24 Blue Tablets: These are the primary active pills in the pack. Each blue tablet contains a combination of two synthetic female hormones: 1 milligram (mg) of norethindrone acetate (a progestin) and 10 micrograms (mcg) of ethinyl estradiol (an estrogen). These hormones work together to suppress ovulation, thicken cervical mucus, and alter the uterine lining to prevent pregnancy.
- 2 White Tablets: These are also active pills, but they contain only one hormone. Each white, hexagonal tablet contains 10 mcg of ethinyl estradiol. This design helps maintain a consistent level of estrogen in the body at the end of the active pill phase.
- 2 Brown Tablets: Found at the very end of the pack, these are the placebo, or inactive, pills. They do not contain any hormones that prevent pregnancy. Instead, each round brown tablet contains 75 mg of ferrous fumarate, which is a form of iron.
The function and purpose of the brown pills
The brown pills serve a very specific, non-contraceptive purpose within the overall regimen of Lo Loestrin Fe. Understanding their function is key to properly taking the medication and trusting the process.
Maintaining a daily habit
One of the most important aspects of any oral contraceptive is consistency. Missing a pill, especially an active one, can increase the risk of pregnancy. The daily regimen of Lo Loestrin Fe is continuous, meaning a new pill is taken every day for 28 days. The brown pills are included for the last two days of the cycle to help users maintain the habit of taking a pill at the same time each day. This prevents confusion and reduces the chance of forgetting to start the new pack of active pills on time.
Iron supplement
The other key ingredient in the brown pills is ferrous fumarate, an iron supplement. While the amount of iron is not enough to treat an existing iron deficiency or anemia, it is a low-dose addition. The iron is included to help replenish the body's iron supply, especially during the time of withdrawal bleeding, which typically occurs while taking the placebo tablets. It is important to note that the FDA states that the ferrous fumarate tablets do not serve a therapeutic purpose related to contraception.
The withdrawal bleed and the placebo week
On a traditional 28-day cycle, the drop in hormone levels during the placebo week triggers a withdrawal bleed, which mimics a regular menstrual period. For Lo Loestrin Fe, this bleeding often occurs while a person is taking the white or brown pills. The specific 24/2/2 pill regimen (24 blue, 2 white, 2 brown) means the hormone-free interval is very short, often resulting in shorter and lighter withdrawal bleeds compared to other oral contraceptives. Some users may even experience no period at all over time, which is a documented possibility with this very low-dose pill. However, if a period is missed and any active pills were also missed, a pregnancy test may be warranted.
What if you miss a brown pill?
Because the brown pills contain no active hormones, missing one or both of them does not affect the contraceptive effectiveness of the medication. If a brown pill is missed, it can simply be discarded. However, it is crucial to start the new blister pack on the correct day to ensure pregnancy prevention continues without interruption.
Comparison of pills in the Lo Loestrin Fe pack
| Pill Color | Hormone(s) Present | Contraceptive Role | Other Ingredients | Timing in 28-Day Cycle |
|---|---|---|---|---|
| Blue | Norethindrone Acetate (1mg) & Ethinyl Estradiol (10mcg) | Prevents pregnancy by suppressing ovulation. | Inactive ingredients including mannitol, cellulose, and FD&C Blue No. 1. | Days 1-24 |
| White | Ethinyl Estradiol (10mcg) | Active; helps maintain consistent estrogen levels towards the end of the active hormone cycle. | Inactive ingredients including mannitol and cellulose. | Days 25-26 |
| Brown | None (Placebo) | None; included as a reminder to maintain the daily routine of pill-taking. | 75mg ferrous fumarate (iron) plus inactive ingredients. | Days 27-28 |
Conclusion
The brown pills in Lo Loestrin Fe are inactive, hormone-free tablets that contain a low dose of ferrous fumarate, an iron supplement. Their primary purpose is to help women maintain the daily habit of taking a pill, thereby preventing missed doses of the active, hormone-containing blue and white tablets. The iron content is intended to replenish the body during withdrawal bleeding, though it's insufficient to treat anemia. When taken correctly, these reminder pills ensure a seamless transition to the next 28-day cycle, but they do not provide contraceptive protection. For any concerns regarding the use or effectiveness of Lo Loestrin Fe, always consult a healthcare provider for personalized medical advice.
For more detailed product information, the official prescribing information can be found on the DailyMed website.
