Many everyday habits, from the painkillers in your medicine cabinet to the lubricant on your nightstand, can quietly interfere with conception. Some of these are well-known, like heavy drinking. Others are surprising, like sitting too long or using the wrong personal care products. Here’s what to cut back on or avoid entirely while you’re trying to get pregnant.
Common Lubricants Can Harm Sperm
This one catches most couples off guard. The majority of water-based lubricants, including widely used brands like KY Jelly and Durex, contain glycerin as a main ingredient. Glycerin penetrates sperm membranes, dissolves the tail structure that allows sperm to swim, and has a direct toxic effect on sperm cells. Even low concentrations applied for just a few minutes can cause damage.
Sperm also need a specific pH range (between 7.2 and 8.5) to move effectively. When the pH drops below 6.0, motility drops significantly. If you need lubrication, look for products specifically labeled “fertility-friendly” that are glycerin-free. Pre-Seed is one example that has been tested and found non-toxic to sperm.
Alcohol Lowers the Odds for Both Partners
More than seven alcoholic drinks per week is the threshold where fertility starts to take a measurable hit. Women who drink at that level are about 7% less likely to conceive. When the male partner drinks that much, the chances of a live birth drop by 9%. These numbers come from women undergoing fertility treatment, but the biology applies broadly: alcohol disrupts hormone signaling in both sexes. If you’re actively trying, keeping well under seven drinks a week for both of you is a straightforward way to improve your odds.
Caffeine in High Amounts
You don’t need to quit coffee entirely, but quantity matters. For women, consuming more than about 233 milligrams of caffeine per day (roughly two standard cups of coffee) is associated with a 36% higher risk of infertility compared to staying under 100 milligrams. For men, the effect is even steeper at high intake: consuming 400 milligrams or more daily is linked to a fivefold increase in the odds of poor sperm quality compared to men who drink under 100 milligrams.
There’s also an early-pregnancy concern. Every additional 100 milligrams of daily caffeine is associated with a 14% increase in miscarriage risk. Since most people don’t know they’re pregnant for several weeks, it makes sense to moderate your intake while you’re trying rather than waiting for a positive test. Staying under 200 milligrams a day (about one and a half regular cups of brewed coffee) gives you a reasonable margin of safety.
Over-the-Counter Painkillers Around Ovulation
Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen work by blocking the production of compounds called prostaglandins. The problem is that a surge in prostaglandins is exactly what your body needs to release an egg from the ovary each month. Taking NSAIDs around the time of ovulation can delay or even prevent that release entirely. One prescription-strength NSAID is actually used clinically to suppress ovulation during certain IVF procedures, which gives you an idea of how real this effect is.
If you need pain relief during your fertile window, acetaminophen (Tylenol) is generally a safer choice since it works through a different mechanism. Save the ibuprofen for the first half of your cycle or after you’ve confirmed ovulation has passed.
Medications That Suppress Sperm Production
Several common prescription medications can significantly reduce sperm count or quality. The biggest culprit is supplemental testosterone. This sounds counterintuitive since testosterone is the primary male sex hormone, but when it comes from an outside source (injections, gels, patches), the brain responds by shutting down the body’s own production, which shuts down sperm manufacturing along with it. The effect can be dramatic, sometimes reducing sperm count to near zero. Other hormonal medications like finasteride (used for hair loss) and dutasteride (used for enlarged prostate) also decrease sperm count and semen volume, though these effects are reversible after stopping.
Certain antidepressants are another category to be aware of. SSRIs like paroxetine and tricyclic antidepressants like clomipramine can suppress sperm production, though this also reverses after discontinuation. Some antibiotics taken at high doses, certain blood pressure medications, and anabolic steroids used for bodybuilding all carry similar risks. If the male partner takes any prescription medication regularly, it’s worth reviewing the list with a doctor before trying to conceive. Never stop a medication without medical guidance, but knowing that alternatives may exist is the first step.
Heat Exposure and Male Fertility
The testicles sit outside the body for a reason: sperm production requires a temperature a few degrees below core body temperature. Regularly raising scrotal temperature interferes with that process. In animal studies, just 20 minutes of exposure to about 109°F (43°C) was enough to trigger cell death in developing sperm.
The practical sources of heat exposure that matter most include hot tubs or hot baths used three or more times per month, saunas at the same frequency, sitting for 10 or more hours per day, using a laptop on your lap for five or more hours daily, and using heated car seats for three or more hours weekly. Tight-fitting underwear also keeps things warmer than necessary. Even fevers can temporarily reduce sperm count and motility, with longer fevers causing more damage. Sperm take about two to three months to fully develop, so heat damage today won’t show up as poor results until weeks later. That also means improvements take time to materialize after you stop the exposure.
Endocrine-Disrupting Chemicals in Everyday Products
A growing body of evidence links certain synthetic chemicals to reduced fertility in both men and women. These chemicals mimic or interfere with your natural hormones, and they show up in a surprising number of household items. The ones most strongly tied to reproductive harm include phthalates (found in plastic containers, personal care products, and some drug coatings), BPA (found in food and beverage packaging, can linings, and some receipts), pesticide residues on food, and certain compounds in detergents, cosmetics, and flame retardants.
Phthalates are particularly concerning for ovarian function. They’re absorbed through ingestion, inhalation, and skin contact, making exposure nearly constant for most people. BPA mimics estrogen by binding to estrogen receptors, which can throw off the hormonal balance needed for ovulation and implantation. You can reduce your exposure by storing food in glass or stainless steel instead of plastic, avoiding microwaving food in plastic containers, choosing personal care products labeled phthalate-free, eating organic produce when possible (especially for items on the “Dirty Dozen” list), and handling thermal receipts less frequently.
Too Much Intense Exercise
Exercise is generally good for fertility, but there’s a ceiling. Women who engage in very intense exercise for more than 60 minutes per day face a higher risk of not ovulating at all. The mechanism involves the body interpreting extreme energy expenditure as a signal that conditions aren’t ideal for pregnancy, which leads to suppressed reproductive hormones and skipped ovulation cycles. Moderate exercise, even daily, doesn’t carry this risk. If you’re a serious athlete or do high-intensity training most days of the week, consider scaling back to moderate-intensity workouts while trying to conceive.
Too Much Preformed Vitamin A
Vitamin A is essential, but the preformed version (retinol, found in supplements and some skincare products like retinoids) becomes dangerous to a developing embryo at high doses. The WHO recommends staying under 10,000 IU of preformed vitamin A per day during the first 60 days of fetal development. Since those 60 days overlap heavily with the period when you might not know you’re pregnant yet, it’s important to check your supplement labels now. Many prenatal vitamins use beta-carotene (a plant-based form the body converts as needed) instead of preformed vitamin A, which avoids this risk entirely. Also check whether you’re using retinol-based skincare products, which are another common source.
High-Mercury Fish
Fish is actually beneficial for fertility thanks to its omega-3 fatty acids and protein, so you don’t want to cut it out. The goal is choosing the right types. The EPA and FDA recommend eating two to three servings per week from lower-mercury options like salmon, shrimp, tilapia, and sardines. Avoid high-mercury species like shark, swordfish, king mackerel, and tilefish entirely. If you eat fish caught recreationally, check local advisories. Larger freshwater fish like carp, catfish, trout, and perch are more likely to carry elevated mercury or other contaminants. When no advisory is available for locally caught fish, limit yourself to one serving that week and skip other fish.