“Postinor 2” is a brand name birth control formulation manufactured in tablets, each of which contains 0.75 mg of the active steroid levonorgestrel. Levonorgestrel is an entirely synthetic progestogen that was synthesized in the 1960s and was included in birth control products by the 1980s. The levonorgestrel within Postinor 2 functions by inhibiting ovulation or fertilization by modifying tubal transport of sperm and/or ova.
Some speculate that it may also decrease endometrial receptivity to the implantation of a fertilized egg. Though administration of Postinor 2 is not regarded as a clinically effective intervention post-uterine implantation, it is suggested to work for up to 72 hours following unprotected sex. In Nigeria, Postinor 2 is ubiquitously available as an over-the-counter emergency.As a result of its efficacy and popularity, it is regarded as an “essential medicine” by the World Health Organization (WHO). Though an incredibly useful and practical medication, Postinor 2 can provoke unwanted side effects such as: breast tenderness, headaches, menstrual irregularities, and nausea. The combination of lingering side effects along with general curiosity has lead many women to ask how long “Postinor 2” stays in their system after taking it.
Can Postinor 2 Delay Period?
Postinor 2 may make your next monthly period later than expected by a few days. If your next menstrual period after taking Postinor 2 is more than 1 week late, check with your doctor right away for a pregnancy test.
How long does “Postinor 2” stay in your system?
To determine how long “Postinor 2” is likely to stay in your system, it is necessary to examine the elimination half-life of its principal ingredient Levonorgestrel. Levonorgestrel is reported to have an elimination half-life of 24.4 hours (+/- 5.3 hours). This indicates that the average Postinor 2 user will have eliminated 50% of the dosage from systemic circulation in just over a day after ingestion.
Knowing the average half-life of 24.4 hours, we can estimate that it’ll take around 5.59 days to completely clear a single Postinor 2 dose from your system. However, research has suggested that there’s an approximate 5.3 hour deviation in elimination half-life among most users. This indicates that some users may exhibit half-lives closer to 19.1 hours, while others may exhibit half-lives closer to 29.7 hours.
Those with faster elimination half-lives of 19.1 hours could clear Postinor 2 from their systems within 4.38 days, while those with slower elimination half-lives could eliminate Postinor 2 within 6.81 days. In other words, most people taking Postinor 2 will have eliminated the levonorgestrel from systemic circulation within a week after single-dose administration. Sources other than the Postinor 2 product labeling suggest that the elimination half-life may be slightly longer than 24.4 hours. See: Can I Take Postinor 2 Twice In A Week
Independent research has suggested an elimination half-life of 28 hours (+/- 6.4 hours) and other evidence suggests that from steady state concentrations, 36 hours (+/- 13 hours) may be more accurate. From the 28 hour half-life with the (+/-) 6.4 hour deviations, we could estimate that elimination may take 6.42 days (on average), but possibly sooner in 4.95 days or later in 7.88 days. If steady state concentrations were attained, average elimination could take 8.25 days (on average), but possibly less time (5.27 days) or a much longer duration (11.23 days).
Most users of Postinor 2 should therefore conclude that the drug is unlikely to still be in their systems after 2 full weeks. Even in the extreme cases of users experiencing a prolonged elimination half-life of 49 hours, the drug should have been eliminated in under 12 days. In summary, most Postinor 2 users will have eliminated the synthetic hormone within 1 week.
Factors that influence how long Postinor 2 stays in your system
Though Postinor 2’s labeling indicates that most individuals should eliminate the levonorgestrel from their system in 5.59 days (on average), it does suggest that there is usually some variation in half-life. When contemplating whether Postinor 2 is likely to stay in your system for a shorter or longer duration than average, it is necessary to consider some variables. Variables that influence how long Postinor 2 stays in your system include: dosage, frequency of administration, individual attributes, and co-administered drugs.
How To Take Postinor 2
The dosage of Postinor 2 that you administer can affect how long it stays in your system. As with most drugs, the greater the dosage you ingest, the longer you can expect it to stay in systemic circulation. Whereas the lower the dosage of Postinor 2 you take, the quicker you can expect it to leave your system (as a general rule of thumb).
If administered at a dosage greater than is medically intended, the half-life of levonorgestrel is likely to exceed its average of 24.4 hours. In other words, someone taking multiple Postinor 2 pills simultaneously or within a short duration may retain the levonorgestrel in circulation for longer than a standard dose user. That said, even if a person were to take three Postinor 2 pills, the levonorgestrel is likely to be eliminated in under 2 weeks.
Frequency of administration
The frequency at which you take Postinor 2 will also affect how long it stays in your system. Someone who takes Postinor 2 every single night is likely to retain the levonorgestrel content for a markedly longer term than a person who takes levonorgestrel only in the case of emergencies. Therefore if you use Postinor 2 more frequently than “just emergencies,” there’s a chance that it may accumulate within your body to a greater extent, leading to a prolonged elimination term.
On the other hand, a person who uses Postinor 2 only in the case of infrequent emergencies (as is medically intended), the levonorgestrel should be eliminated in under 6 days (on average). Increased frequency of administration elevates serum concentrations of levonorgestrel, resulting in increased likelihood of levonorgestrel accumulation within bodily tissues. Should levonorgestrel accumulate in bodily tissues of frequent users, its elimination half-life is likely to be prolonged.
Research already shows that steady state concentrations of levonorgestrel are attained within 9 days of administration and that the steady state half-life is prolonged. Should you have taken Postinor 2 for over 9 days straight, it’ll likely take between 1 and 2 weeks to eliminate levonorgestrel from your system after discontinuation. In addition to accumulation in serum and bodily tissue, it is possible that frequent administration is more taxing on hepatic and renal function.
If you were to take Postinor 2 frequently, there’s a chance that hepatic metabolism would be less efficient than usual as a result of the increased quantity of levonorgestrel ingested (as a result of frequent dosing). This increased quantity of levonorgestrel would likely tax hepatic enzymes and decrease the efficiency of metabolism, leading to prolonged elimination. Furthermore, increased frequency of administration will yield a greater number of levonorgestrel metabolites circulating throughout your system at a time – all of which will necessitate excretion.
The heighted number of metabolites among frequent users of Postinor 2 may tax the kidneys to a greater extent, thereby diminishing excretion speed. If you use Postinor 2 on an infrequent basis, the levonorgestrel should be eliminated with efficiency in under 6 days. However, if you’re a frequent user that may have attained steady state concentrations, expect it to remain in your system for a longer period (possibly up to 2 weeks).
Individual factors
Hypothetically speaking, two women could simultaneously ingest a single-dose of Postinor 2, yet the exact elimination speed among these women would likely differ. The difference in elimination speed may be minor (e.g. a matter of minutes), but could also be more significant (e.g. many hours). These differences in elimination speeds are typically dictated by individual factors such as a person’s body mass, genetics, hepatic function, and renal function.
Body mass + Fat (%): It is understood that levonorgestrel is highly lipophilic, meaning it is soluble in fat. This makes it increasingly likely to accumulate among users that are obese and/or have a high percentage of body fat, especially when administered frequently over an extended term. Should woman with a high BMI take levonorgestrel daily for several weeks, her elimination term would likely exceed the elimination term of a woman with a low BMI.
This is because the woman with a low BMI will experience altered distribution, protein binding, metabolism, and renal excretion of levonorgestrel compared to the high BMI user. Furthermore, propensity of levonorgestrel accumulation will be reduced among women with low BMIs because there are fewer fat stores to retain levonorgestrel for an extended duration. Though differences in half-lives among obese and non-obese Postinor 2 users may not always be clinically significant, they will likely differ.
Genetics: Though the exact pharmacokinetics of levonorgestrel haven’t been elucidated in humans, it is metabolized by CYP450 (cytochrome P450) hepatic enzymes. Since it is understood that alleles of CYP-genes influence the function of CYP450 enzymes, it is likely that metabolism of levonorgestrel may differ among users based on CYP alleles. Though researchers initially speculated that CYP3A4*1B and CYP3A5*3 polymorphisms may alter metabolism and elimination of levonorgestrel, no conclusive evidence supports this speculation.
However, researchers did note that there was significant interindividual variability in plasma concentrations of levonorgestrel, some of which is likely a result of allelic polymorphisms. Therefore it is necessary to consider that certain polymorphisms of CYP450-genes may dictate the metabolism, serum concentrations, and half-life of levonorgestrel. A poor metabolizer of Postinor 2 as a result of decreased CYP450 function (stemming from allelic expression) would likely exhibit an increase in levonorgestrel half-life, eliminating it at a slower than average pace.
Hepatic function: The degree to which your liver is healthy may also impact the duration Postinor 2 is likely to stay in your system. A person with hepatic impairment as a result of a condition like cirrhosis is unlikely to efficiently metabolize levonorgestrel. This poor metabolism of levonorgestrel is likely to increase serum concentrations and contribute to prolonged elimination after administration.
Individuals with compromised hepatic function will exhibit reductions in CYP450 enzyme function. Usually this reduction in enzymatic function of CYP450 is directly proportional to the degree of hepatic impairment. A person with mild hepatic impairment may retain levonorgestrel for slightly longer than average, whereas an individual with severe hepatic impairment may retain levonorgestrel for substantially longer than average.
Metabolic rate: A person’s BMR (basal metabolic rate) is likely to have a slight influence on how long Postinor 2 stays in their system. If you have a high BMR, it is known that your body is essentially burning more energy in a resting state than someone with a low BMR. This increased energy expenditure tends to expedite metabolism and elimination of exogenous substances.
In cases of hyperthyroidism associated with an extremely high BMR, drugs are often eliminated substantially quicker than average. In cases of hypothyroidism associated with a low BMR, drugs are eliminated slower than average. Though most users are unlikely to be at the extremes of BMR associated with thyroid dysfunction, whether you have a high or low BMR may have a modest impact on levonorgestrel elimination.
Other drugs: It is well-documented that levonorgestrel interferes with the metabolism of other drugs, but on the flipside, it is important to acknowledge that other agents (whether it be drugs or supplements) could alter the metabolism of levonorgestrel. Since levonorgestrel is thought to be metabolized by CYP450 isoenzymes such as CYP3A4 and CYP1A2 – any co-administered agent that affects the function of the aforementioned isoenzymes will alter the kinetics of levonorgestrel.
A drug that serves to interfere with CYP3A4, CYP3A5, or CYP1A2 function would be classified as an “inhibitor.” Examples of respective inhibitors of CYP3A4 and CYP1A2 include: Ritonavir and Luvox. If you were to take a CYP3A4 or CYP1A2 inhibitor along with Postinor 2, there’s a chance that the drug would remain in your system for longer than usual as a result of altered metabolism.
Conversely, a drug that enhances function of these various isoenzymes would be considered an “inducer.” Examples of respective inducers of CYP3A4 and CYP1A2 include: Modafinil and tobacco. Should you have taken an inducer along with Postinor 2, it may expedite metabolism of levonorgestrel leading to faster elimination.
Renal function: A majority of each Postinor 2 dosage is excreted via the kidneys. If you have compromised renal function, it is possible that you may retain levonorgestrel metabolites for a longer duration than usual. Renal impairment is known to cause accumulation of exogenous substances prior to their elimination, potentially contributing to reabsorption and redistribution throughout the body.
The extent to which your kidney function is impaired may be reflective upon how long Postinor 2 stays in your system. Someone with a mild form of renal impairment may eliminate levonorgestrel with relative efficiency compared to someone with more significant impairment. If your kidney function is optimal, excretion of levonorgestrel metabolites should remain efficient.
Postinor 2: Absorption, Metabolism, Excretion (Details)
Following oral administration of Postinor 2, its synthetic steroid “levonorgestrel” is rapidly absorbed with a bioavailability of approximately 100%. In around 1.6 hours after ingestion, plasma concentrations of levonorgestrel peak at approximately 14.1 ng/ml. Up to 99% of levonorgestrel binds to plasma proteins, particularly sex hormone binding globulin (SHBG) and albumin, and is distributed at a volume of 1.8 liters per kilogram.
Unlike many pharmaceutical drugs, it is not subject to extensive hepatic first-pass metabolism. However, some of the levonorgestrel is broken down by CYP450 isoenzymes and undergoes reduction of the delta-4 and 3-oxo group, as well as hydroxylation at 2-alpha, 1-beta, and 16-beta positions. This is followed by conjugation at the 17-beta-OH position to facilitate formation of sulfates and (to a lesser extent) glucuronides.
Tips to clear Postinor 2 from your system
If you’re looking to eliminate Postinor 2 from your system as soon as possible, there may be some tricks that can be used. It is necessary to caution that none of these tips should be implemented immediately after taking Postinor 2. Furthermore, should you consider implementing any of the strategies below as a means of detoxification, you should first confirm safety and alleged efficacy with a medical professional.
Physical exercise: Perhaps the least harmless suggestion here is to ramp up physical exercise in attempt to burn body fat. Though short-term fat burning is unlikely to have significant implications for the pharmacokinetics of Postinor 2, it may slightly expedite the elimination of levonorgestrel and its metabolites. This may be especially helpful for women who have a high percentage of body fat that may have taken Postinor 2 for a long duration (as to accumulate levonorgestrel within adipose tissue).
Calcium-d-glucarate: The supplement calcium-d-glucarate may aid in the renal excretion of Postinor 2, providing your kidneys with extra support. Calcium-d-glucarate acts as a beta-glucuronidase inhibitor which essentially allows for the clearance of molecules within detoxification pathways. Though this may not dramatically improve renal excretion speed of Postinor 2, it will likely aid in general detoxification.
Activated charcoal: Another supplement to consider whenever discontinuing any drug that you believe is still in your system is to take activated charcoal. Should any Postinor 2 have accumulated within your body to a significant extent, activated charcoal will bind to it and/or toxins that it may have created. Always ask your doctor when it is safe to take activated charcoal as this supplement can interfere with absorption of other medications you may be taking.
Modification of pH: The degree to which Postinor 2 is acid labile is unknown. However, it could be hypothesized that acidification of urinary pH may expedite the elimination of levonorgestrel from your system. Acidification of urine can be accomplished via dietary modifications and/or ingestion of supplements to deliberately increase pH. If Postinor 2 happens to be acid labile, much of the drug may be destroyed in an acidic environment and urinary excretion may be expedited.
How long has Postinor 2 stayed in your system after stopping?
If you took Postinor 2, share a comment mentioning how long you believe it stayed in your system. Do you think that the levonorgestrel component lingered in your system for longer than 6 days? Or do you think that you were able to eliminate most of it in a shorter duration? Many women speculate that Postinor 2 stays in their body for longer than is medically reported due to the side effects that are experienced.
While there is some variation in elimination time among users (possibly by several days), in the vast majority of Postinor 2 users, it should be out of the plasma within 1 to 2 weeks after cessation. In the event that a woman were to ingest high doses of Postinor 2 frequently for a long-term, it could take longer than 2 weeks to eliminate from the plasma. Since most women take standard dosages within proper medical guidelines, elimination shouldn’t be protracted.
If you suspect that Postinor 2 may still be in your system due to the fact that you’re still experiencing side effects from its administration, realize that side effects can linger after a drug has been eliminated. The levonorgestrel can induce neurophysiologic changes and it may take your body awhile to readjust itself back to homeostasis – even though the drug is no longer in your plasma. Should you have any further concern about Postinor 2 staying in your system for an abnormally long duration, consult a medical professional. SEE: Gynaecosid
