You likely know that you need to be careful about what medications you take when you’re pregnant. But the information isn’t as straightforward for when you’re still trying. This article explains common OTC drugs and considerations for when you’re trying to conceive.

NSAIDs

Ibuprofen is one of the most commonly used OTC nonsteroidal anti-inflammatory drugs (NSAIDs). It is a popular pain reliever, especially for severe period cramps. Over-the-counter NSAIDs include:

AspirinAdvil, Motrin (ibuprofen)Aleve (naproxen)

While animal studies have previously suggested that NSAIDs may interfere with ovulation, human studies are less clear. There have even been studies that have found that aspirin may increase the probability of conception. That said, aspirin has its risks, so you should never take it as a means of increasing fertility. “I am unaware of definitive proof that any OTC medication reduces or improves the likelihood of conception,” says Kevin Doody, MD, a reproductive endocrinologist at the Center for Assisted Reproduction (CARE Fertility) in Dallas, Texas. “The exception to this is that we know NSAID class drugs can impair the rupture of the follicle and release of the egg. Indomethacin [a prescription NSAID] specifically has been shown to cause luteinized unruptured follicle syndrome (LUFS),” says Doody. LUFS is when an egg isn’t released from the follicle at ovulation.

NSAIDs and Ovulation

To understand the potential impact NSAIDs may have on ovulation, you must understand how follicles work. Ovarian follicles are fluid-filled sacs that contain immature eggs. During ovulation, an egg matures and causes the follicle to break open to release the egg, a natural inflammatory action of the body. So, while you might think of inflammation as “bad,” in this case, inflammation seems to be required for healthy ovulation. Since NSAIDs suppress inflammation, it’s possible they could suppress this necessary inflammation, too. But before you throw away all your ibuprofen, be aware that an occasional dose is unlikely to make a significant impact. Studies on NSAIDs’ impact on ovulation have shown mixed results. Delayed Ovulation In an older, randomized crossover trial, 12 women took 800 mg of ibuprofen three times a day for 10 days. They took the pain relievers during the first half of their cycle (the follicular stage) before ovulation. Researchers found that the NSAIDs significantly delayed ovulation. However, this was a small study with just 12 women. They were also taking high doses of the drug for several days, which doesn’t represent typical use. Early Ovulation Prevention A more extensive, more recent study examined whether NSAIDs could help prevent premature ovulation during an IVF cycle. This study was important because an IVF cycle must be canceled if ovulation occurs before the eggs can be retrieved. This study of approximately 1,800 cycles did find that NSAID drugs could help prevent early ovulation. So, in this case, NSAIDs helped prevent IVF cycle cancelations. However, the results also show that NSAIDs could delay ovulation, potentially when it’s not so valuable. Reduced Risk of Anovulation Not all research shows NSAIDs are bad for ovulation. In an observational study of 175 women, researchers evaluated pain relievers’ impact on reproductive hormones and ovulation. Almost 70% of participants said they used OTC pain relievers, including ibuprofen, acetaminophen, aspirin, and naproxen. Those who reported using any pain relief medication during the first half of their cycle were less likely to have an anovulatory cycle (a cycle where they did not ovulate). So, the pain medications seemed to be associated with a lower risk of ovulatory problems. In this case, the OTC drug may have helped fertility. So, what should you do? The occasional ibuprofen or NSAID is unlikely to cause fertility problems, but it’s probably best to avoid it when possible.

Ibuprofen and Testosterone

NSAIDs may also affect male fertility. In a small clinical trial, 31 men took prolonged, high doses of ibuprofen. This dosage replicated how athletes may take the drug. The study extended over six weeks and involved taking 600 mg of ibuprofen twice daily. After just 14 days of ibuprofen use, some men taking ibuprofen developed an induced state of compensated hypogonadism. This condition is when the ratio of testosterone to LH hormone is not in balance, which could theoretically lead to a lower sperm count. This particular study, however, did not conduct sperm count testing to confirm. So, should male partners avoid ibuprofen and other NSAIDs while trying to conceive? “I think taking an occasional Advil is fine,” says urologist and male fertility specialist James M. Hotaling, MD, MD, FECSM, of Reproductive Medicine Associates of New Jersey. “The effect was only seen after prolonged exposure. More work is needed before we can make firm conclusions.” But how much is too much ibuprofen? “I think they should become concerned if they are taking high doses of ibuprofen or Tylenol for a long period, for over two weeks,” says Hotaling. Still, not all pain relievers are off the hook, especially prescription narcotics. “Men should not take narcotics while trying to conceive as this can alter the male hormone axis and cause problems with sperm,” Hotaling says.

Cough Medicines

Cough medicines work in a couple of different ways. Some are expectorants that work by thinning and breaking up mucus to be easier to expel. Others are suppressants that keep you from coughing.

Guaifenesin (Mucinex)

If you’ve spent any time in fertility forums or social media groups, you may have heard that the expectorant guaifenesin (found in brand name over-the-counter drugs like Mucinex) can help female fertility. Specifically, some people claim that it improves cervical mucus quality. This myth likely originates from the function of the drug, which is to thin mucus to make it easier to expel. There’s little to no evidence, however, that this is true. “The idea that guaifenesin might promote fertility through increased production of cervical mucus has been around for decades,” explains Doody. “I am unaware of any proof that this is true. I don’t know any fertility specialists that recommend it.” During pregnancy, it is unclear if guaifenesin carries risks. The FDA has assigned it a category C rating, which means there may be risks but there are not sufficient human studies to confirm them. If you think you could be pregnant, it may be best to avoid this drug or discuss it with a doctor first.

Dextromethorphan

Dextromethorphan (DXM) is a cough medicine you should likely stay away from when you’re trying to get pregnant. DXM is a cough suppressant found in some popular cold medications, including Robitussin. This medication is not recommended during pregnancy because animal studies have found possible fetal risks. While that doesn’t mean it will harm a fetus, to be safe, it’s best to avoid DXM during pregnancy, including when you might be pregnant.

Antihistamines and Allergy Medicines

Antihistamines are drugs that block histamines, a chemical your body produces in response to allergens. Antihistamines treat allergy symptoms, especially runny nose, congestion, itchy and watery eyes, and hives. Common OTC antihistamines include:

Allegra (fexofenadine)Benadryl (diphenhydramine)Chlor-Trimeton (chlorphenamine)Claritin (loratadine)Zyrtec (cetirizine)

While some claim that allergy medicines may interfere with fertility, there is currently no evidence to support those claims. Some concerns people have about allergy drugs include:

Interference with implantation: Some people worry that allergy medications, specifically antihistamines, may interfere with embryo implantation. However, there is currently no evidence that antihistamines have an effect on implantation. Dry cervical mucus: Another concern is that many allergy medications dry up mucus (to stop your runny nose). Some people worry that may also lead to less fertile quality cervical mucus. But, again, there’s no hard evidence that allergy medications interfere with your ability to get pregnant.

To be on the safe side, however, avoiding allergy medications when you’re trying to get pregnant, and especially during fertility treatment, is probably wise. But it may not be necessary. Talk to a doctor about what’s best for you.

OTC Drugs and the 2-Week Wait

Nearly every OTC medication contains a warning label that advises pregnant and breastfeeding people to discuss the medication with a doctor before use. That’s because all medications pose potential risks to fetuses and breastfeeding babies just as they do to the adults who take them. “It is true that these commonly used OTC drugs are unlikely to have an immediately recognizable impact [e.g., major birth defects],” Doody continues. “It is impossible to adequately study the subtle impacts that these substances may cause. An example of this is the controversy that now surrounds Tylenol use during pregnancy. Speech delay is subtle. NSAID-type drugs also appear to affect the testicles of male fetuses,” says Doody. How does that apply during the two-week wait? Technically, you’re already in week three or four of your pregnancy after fertilization. So should you act like you’re pregnant during the two-week wait? Doody says yes: “The embryo is likely vulnerable during this time.”

Summary

OTC medications may carry certain risks when you are trying to conceive. While some risks involve fertility, most studies that indicate potential fertility issues are small and have mixed results. However, many OTC drugs do carry risks to a fetus. So if you could be pregnant, especially during the two-week wait between ovulation and your expected period, it may be good to avoid OTC medicines as much as possible.

A Word From Verywell

Only you and a doctor can decide whether the benefits outweigh the possible risks of a particular medication while trying to conceive and during pregnancy. If you are currently taking medication, especially a prescription drug, don’t stop taking it without talking to a doctor first. It can be dangerous to discontinue some medications suddenly. Therefore, it may be better for you (and your baby) to continue—even if you’re trying to conceive or are pregnant.