No single pill guarantees pregnancy, but several prescription medications and over-the-counter supplements can meaningfully improve your chances. The right option depends on why you’re having trouble conceiving. Ovulation problems, hormonal imbalances, egg quality, and uterine lining issues each respond to different treatments.
Prescription Ovulation Medications
If you’re not ovulating regularly, or not ovulating at all, ovulation-inducing medications are the most effective pills for helping you get pregnant. Two oral medications dominate this category, and both are taken for five days early in your menstrual cycle (typically days 3 through 7).
Letrozole
Letrozole works by temporarily lowering your estrogen levels, which tricks your brain into ramping up the hormones that trigger egg development. It also appears to make your ovarian follicles more responsive to stimulation. In women with polycystic ovary syndrome (PCOS), letrozole produced a clinical pregnancy rate of about 26% per cycle, with an ongoing pregnancy rate of 23%. Many fertility specialists now consider it the preferred first-line option for ovulation induction.
Clomiphene Citrate (Clomid)
Clomiphene has been used for decades and works through a similar feedback loop, blocking estrogen receptors in the brain so your body produces more follicle-stimulating hormone. It achieves ovulation rates around 61% per cycle, similar to letrozole. However, its clinical pregnancy rate per cycle is lower, around 13%, partly because clomiphene can thin the uterine lining, making implantation harder. If your lining measures under 5 mm on clomiphene, your doctor may switch you to letrozole.
Both medications carry a higher chance of twins. Clomiphene carries roughly an 8% chance of a multiple pregnancy (about 1 in 12 cycles). That risk is worth understanding before you start treatment.
Side Effects of Fertility Medications
Mood changes are the side effect women ask about most. Both letrozole and clomiphene can cause anxiety, irritability, and nervousness. Some women on letrozole experience confusion or, rarely, depressive symptoms. Vision changes, including blurred or decreased vision, are an uncommon but recognized side effect of both drugs. If you notice any visual disturbances, that warrants a call to your prescriber right away.
Hot flashes, headaches, and bloating are common with both medications. These side effects are temporary, lasting only during and shortly after the five-day dosing window.
Insulin-Sensitizing Options for PCOS
If you have PCOS, insulin resistance is often the underlying reason you’re not ovulating. Two options target this directly: metformin (a prescription medication) and myo-inositol (an over-the-counter supplement).
Myo-inositol at 4 grams per day (split into two 2-gram doses) improves insulin sensitivity and menstrual cycle regularity with effectiveness comparable to metformin. In head-to-head studies, myo-inositol was actually superior to metformin for restoring regular periods, with nearly three times the odds of returning to regular menstruation. It’s also better tolerated, since metformin frequently causes nausea, diarrhea, and stomach cramps that lead some women to stop taking it.
The most studied formulation combines myo-inositol with a small amount of D-chiro-inositol in a 40:1 ratio (4 grams of myo-inositol plus 100 mg of D-chiro-inositol daily). Research also shows that combining myo-inositol with metformin works better than either one alone. If you have PCOS and your doctor prescribes letrozole or clomiphene, adding an insulin-sensitizing agent can improve the results.
Supplements That Support Egg Quality
CoQ10 (Ubiquinol)
Your egg cells contain roughly 100,000 mitochondria each, far more than any other cell in your body. These mitochondria produce the energy needed for fertilization and early embryo development. As you age, both mitochondrial function and natural CoQ10 levels decline in your eggs, contributing to lower fertility.
CoQ10 supplementation helps by supporting mitochondrial energy production and reducing oxidative damage to your eggs’ DNA and proteins. Research using 150 mg per day of ubiquinol (the active form of CoQ10) over four months showed improvements in key reproductive hormones. Many fertility clinics recommend CoQ10 as part of a preconception supplement plan, particularly for women over 35.
Folic Acid
Folic acid doesn’t directly improve your chances of conceiving, but it’s the single most important supplement to start before pregnancy. The CDC recommends 400 mcg daily for all women who could become pregnant, to prevent neural tube defects that develop in the earliest weeks, often before you know you’re pregnant. If you’ve had a previous pregnancy affected by a neural tube defect, the recommended dose increases to 4,000 mcg daily.
Chasteberry (Vitex)
Chasteberry extract works on dopamine receptors in the brain to lower prolactin levels. Elevated prolactin can shorten the second half of your menstrual cycle (the luteal phase), making it harder for a fertilized egg to implant. In a placebo-controlled trial, women taking 20 mg daily of chasteberry extract for three months saw their luteal phase lengthen by five days and their progesterone levels normalize. Several pregnancies occurred across clinical trials, though the studies were small. Side effects are mild and infrequent, mostly headaches and occasional skin reactions.
Chasteberry is most likely to help if you have mildly elevated prolactin or a short luteal phase. It’s not a replacement for prescription ovulation medications if you’re not ovulating at all.
Progesterone for Uterine Lining Support
Even after ovulation, pregnancy requires a thick, receptive uterine lining for the embryo to implant. Progesterone is the hormone responsible for building up that lining in the second half of your cycle. If your luteal phase is too short or your progesterone levels are low, your doctor may prescribe progesterone supplements in oral, vaginal, or injectable form to support implantation. This is sometimes prescribed alongside ovulation medications, particularly during medicated cycles or after procedures like intrauterine insemination.
When to Seek Prescription Help
Clinical guidelines recommend a fertility evaluation after 12 months of regular unprotected intercourse if you’re under 35, after 6 months if you’re between 35 and 40, and immediately if you’re over 40. Conditions like known fallopian tube damage, a history of pelvic inflammatory disease, or previous ectopic pregnancy also warrant immediate evaluation regardless of age.
Over-the-counter supplements like myo-inositol, CoQ10, folic acid, and chasteberry are reasonable to start on your own while you’re trying. But if you suspect you’re not ovulating, if your cycles are very irregular or absent, or if you’ve been trying for the timeframes above without success, prescription medications offer substantially higher pregnancy rates per cycle than supplements alone. Starting with the right intervention early, rather than spending months on approaches that don’t match your specific issue, saves time that matters more the older you get.