The most important thing you can start taking before trying to conceive is a prenatal vitamin with at least 400 micrograms of folic acid, ideally one to three months before you start trying. Beyond that core recommendation, several other supplements and prescription medications can meaningfully improve your chances depending on your situation, from over-the-counter options like CoQ10 and inositol to prescription ovulation drugs.
Folic Acid: The Non-Negotiable Starting Point
Folic acid doesn’t directly boost your odds of conceiving, but it’s the single most important supplement to start before pregnancy. Taking 400 micrograms daily helps prevent neural tube defects, which are serious birth defects of the brain and spine that develop in the earliest weeks of pregnancy, often before you even know you’re pregnant. The CDC recommends starting at least one month before conception, though many practitioners suggest beginning three months out.
If you’ve had a previous pregnancy affected by a neural tube defect, the recommended dose jumps to 4,000 micrograms daily, starting one month before conception and continuing through the first trimester. Most standard prenatal vitamins contain the baseline 400 micrograms, so taking one daily covers this need along with iron, calcium, and other nutrients that support early fetal development.
CoQ10 for Egg Quality
Coenzyme Q10 is one of the most evidence-backed supplements for women trying to improve egg quality, particularly after age 35. It works inside the mitochondria of your egg cells, helping them produce the energy they need to mature properly and divide correctly after fertilization. As you age, your eggs’ mitochondria become less efficient, and CoQ10 levels naturally decline. Supplementing helps compensate for that drop.
The dosing depends on your situation. For women with normal ovarian reserve, 200 mg daily for at least 30 to 35 days before trying to conceive is a common recommendation in clinical studies. Women with diminished ovarian reserve have seen better results at 600 mg daily for 60 days. For women 35 and older, or those with early signs of declining egg reserve, 200 mg daily for at least 90 days gives the supplement enough time to affect egg development, since eggs take roughly three months to mature before ovulation.
Higher levels of CoQ10 in follicular fluid (the liquid surrounding developing eggs) have been associated with better embryo development and higher pregnancy rates in fertility treatment cycles. While most of the strongest data comes from women undergoing IVF, the biological mechanism applies to natural conception too.
Vitamin D: A Common Deficiency Worth Checking
Vitamin D deficiency is widespread, and it appears to directly affect your ability to conceive. Research on IVF outcomes found that implantation and pregnancy rates increased in step with vitamin D levels. Women with blood levels at or above 30 ng/mL had the best outcomes, while those below 20 ng/mL fared significantly worse.
A simple blood test can check your levels. If you’re below 30 ng/mL, supplementation with vitamin D3 is straightforward and inexpensive. Many prenatal vitamins contain some vitamin D, but not always enough to correct a true deficiency.
Inositol for PCOS
If you have polycystic ovary syndrome, inositol is one of the most effective over-the-counter options available. Two forms matter: myo-inositol and D-chiro-inositol. They work together to improve how your body responds to insulin, which is a core problem in PCOS. When insulin levels are too high, they drive the ovaries to produce excess testosterone, which disrupts ovulation.
The ratio between the two forms matters more than most supplement labels suggest. A 3.6:1 ratio of myo-inositol to D-chiro-inositol has outperformed the more common 40:1 ratio by a wide margin. In a randomized trial of women with PCOS undergoing fertility treatment, the 3.6:1 group had a 65.5% pregnancy rate and a 55.2% live birth rate, compared to just 25.9% and 14.8% in the 40:1 group. That same ratio has also been shown to regularize menstrual cycles and reduce insulin resistance.
Omega-3 Fatty Acids
Fish oil supplements containing EPA and DHA may support fertility through several pathways. In animal research, omega-3 supplementation has been shown to influence the hormonal signaling involved in follicle development, egg maturation, ovulation, and even implantation. Omega-3s alter prostaglandin production, which affects inflammation and blood flow to reproductive tissues. While the human evidence is still catching up to the animal data, omega-3s carry minimal risk and offer broad health benefits that make them a reasonable addition to a preconception routine.
Prescription Medications That Induce Ovulation
When supplements aren’t enough, prescription fertility medications can directly trigger ovulation. The most commonly prescribed first-line option is clomiphene citrate, often known by its brand name Clomid. It works by blocking estrogen receptors in the brain, which tricks your body into producing more of the hormones that stimulate your ovaries to release an egg.
The standard starting dose is 50 mg daily for five days, typically beginning a few days after your period starts. About 57% of women with ovulation problems ovulate during their first cycle at this dose, and some studies report ovulation rates as high as 75 to 80% across multiple cycles. Ovulation doesn’t guarantee pregnancy, but it removes one of the biggest barriers.
Letrozole is another prescription option that works through a slightly different hormonal pathway and has become increasingly popular, especially for women with PCOS. Your doctor can help determine which is the better fit based on your specific diagnosis.
Metformin for Insulin-Related Infertility
For women with PCOS whose infertility is linked to insulin resistance, metformin can help restore ovulation. It reduces the amount of glucose your liver produces, which lowers circulating insulin levels. Since excess insulin acts directly on the ovaries to promote testosterone production and disrupt normal follicle development, bringing insulin down can restart the ovulation process.
Metformin also appears to work directly within the ovary itself, reducing the number of small cysts while increasing the proportion of follicles that mature to the point of ovulation. The typical dose used in fertility studies is around 1,500 mg daily. It’s sometimes prescribed alone but is often combined with clomiphene or letrozole for a stronger effect.
Progesterone Support After Conception
Progesterone doesn’t help you get pregnant, but it can help you stay pregnant if you have a history of miscarriage. Your body naturally produces progesterone after ovulation to prepare the uterine lining for implantation and sustain early pregnancy. When levels are insufficient, the pregnancy may not hold.
The PRISM trial, a large randomized study, tested vaginal progesterone in women experiencing early pregnancy bleeding. Overall, the benefit was modest. But in a specific group, the results were striking: women with three or more previous miscarriages who took progesterone had a 72% live birth rate compared to 57% in the placebo group. For women with any history of miscarriage combined with early bleeding, progesterone raised live birth rates from 70% to 75%.
Progesterone supplementation is typically prescribed rather than taken on your own, since the timing and form matter. If you have a history of recurrent loss, it’s worth discussing before you conceive so a plan is in place early.
When to Start and What to Prioritize
The ideal preconception window is three months before you start trying. This gives supplements like CoQ10 enough time to influence egg quality through a full maturation cycle, allows folic acid to build up in your system, and gives you time to test and correct any vitamin D deficiency. At minimum, start a prenatal vitamin with folic acid one month before conception attempts.
If you’re under 35 with regular cycles and no known conditions, a prenatal vitamin, CoQ10, vitamin D (if low), and omega-3s form a solid foundation. If you have PCOS, adding inositol at the 3.6:1 ratio is well supported. If you’re not ovulating or haven’t conceived after several months of trying, prescription options like clomiphene or letrozole are the logical next step. Each layer builds on the last, and the right combination depends on what’s standing between you and a positive test.