Supplements During Pregnancy: What's Safe and What to Avoid

Understanding FDA Pregnancy Categories

The FDA historically classified drugs into pregnancy risk categories (A, B, C, D, and X) based on available evidence of fetal risk. While this system was replaced in 2015 by the Pregnancy and Lactation Labeling Rule (PLLR), which requires more detailed narrative descriptions of risk, the category framework remains useful for understanding the spectrum of evidence.

Category A means adequate, well-controlled studies in pregnant women have failed to demonstrate risk to the fetus. Category B means animal studies have shown no risk but there are no adequate human studies, or animal studies showed adverse effects but adequate human studies did not. Category C means animal studies have shown adverse effects and there are no adequate human studies — the supplement should only be used if potential benefit justifies potential risk. Categories D and X indicate demonstrated fetal risk and are generally contraindicated.

It's critical to understand that dietary supplements are not evaluated by the FDA with the same rigor as pharmaceuticals. Supplements do not go through the pre-market approval process, and most have not been formally assigned pregnancy categories. This means that for many supplements, the evidence regarding pregnancy safety is limited, preliminary, or based on traditional use rather than controlled clinical trials.

Magnesium During Pregnancy: What ACOG Says

Magnesium is one of the better-studied minerals in the context of pregnancy. The American College of Obstetricians and Gynecologists (ACOG) recognizes magnesium sulfate as a standard treatment for preeclampsia and eclampsia, and magnesium supplementation has been studied in the context of pregnancy-related leg cramps, preterm labor risk, and general fetal development.

Makrides et al. (2014) conducted a Cochrane systematic review examining magnesium supplementation during pregnancy. The review, which included multiple randomized controlled trials, found that magnesium supplementation during pregnancy was associated with reduced risk of low birth weight and preterm birth in some populations, particularly in women with lower baseline magnesium status. The authors noted that oral magnesium supplementation appeared to be well-tolerated.

The Recommended Dietary Allowance (RDA) for magnesium increases during pregnancy: from 310-320mg per day for non-pregnant women aged 19-30 to 350-360mg per day during pregnancy. Dalton et al. (2016), publishing in Nutrients, noted that many pregnant women do not meet this increased requirement through diet alone, particularly in Western populations where magnesium-rich foods are under-consumed.

However — and this is important — the form, dose, and timing of magnesium supplementation during pregnancy should always be determined in consultation with your healthcare provider. What is appropriate for one pregnancy may not be appropriate for another, depending on individual health status, medications, and gestational factors.

Ingredients to Discuss With Your OB

Not all ingredients commonly found in recovery or wellness supplements have established safety profiles during pregnancy. Here is a general framework — not a recommendation — for how to think about common supplement ingredients in the context of pregnancy:

Folate / Folic Acid: Widely recommended during pregnancy. The CDC recommends 400mcg daily starting at least one month before conception and continuing through early pregnancy to reduce the risk of neural tube defects. This is one of the most well-established supplement recommendations in prenatal care.

Iron: Often recommended during pregnancy due to increased blood volume. ACOG recommends screening for iron deficiency anemia and supplementing as appropriate. Doses should be guided by your provider based on lab results.

Creatine: Creatine monohydrate has an extensive safety profile in non-pregnant populations, and emerging preclinical research has explored creatine's potential neuroprotective role during fetal development. Ellery et al. (2016) published preclinical research in BMC Pregnancy and Childbirth exploring maternal creatine supplementation. However, human clinical trials during pregnancy are limited, and creatine supplementation during pregnancy should only be considered under direct medical supervision and guidance.

L-Theanine: L-theanine has been studied primarily in non-pregnant adults. While it is naturally present in tea (which is generally considered safe in moderate amounts during pregnancy), concentrated L-theanine supplementation has not been extensively studied in pregnant populations. Discuss with your provider before use.

Herbal Supplements (including chamomile): Many herbal supplements lack adequate safety data during pregnancy. Chamomile, while commonly consumed as tea, contains compounds (including apigenin) that have been studied for their effects on uterine tissue. The Natural Medicines Comprehensive Database rates chamomile as "possibly unsafe" in medicinal amounts during pregnancy. Always discuss herbal supplements with your provider.

Tart Cherry: Tart cherry as a food is generally considered safe during pregnancy. However, concentrated tart cherry extracts or supplements have not been extensively studied in pregnant populations. As with any supplement during pregnancy, discuss with your healthcare provider.

Why "Always Consult Your Healthcare Provider" Isn't a Cop-Out

In supplement marketing, the phrase "consult your healthcare provider" is sometimes used as a legal checkbox rather than genuine guidance. We want to be direct about why we mean it sincerely in the context of pregnancy.

Pregnancy involves a developing human being whose physiological systems are being built from scratch. The placenta does not filter out all substances — many compounds cross the placental barrier and reach the fetus. The effects of a compound on a developing fetus may be entirely different from its effects on an adult. Dose-response relationships change. Metabolism changes. Drug and supplement interactions change. What is beneficial in one trimester may be inappropriate in another.

Your obstetrician or midwife has access to your complete health history, your lab results, your medication list, and the specific context of your pregnancy. They can evaluate a supplement in the context of your individual situation — something no blog post, however well-researched, can do. No amount of published research replaces individualized medical guidance during pregnancy.

A General Safety Framework

While specific recommendations must come from your provider, here are general principles that the medical literature supports for thinking about supplements during pregnancy:

1. Prioritize well-studied essentials. Prenatal vitamins containing folate, iron, calcium, vitamin D, DHA, and iodine have the strongest evidence base and the broadest medical consensus for use during pregnancy.

2. Be cautious with concentrated extracts. A compound that is safe as a food (like chamomile tea or tart cherry juice) may have a different risk profile when concentrated into supplement form. Dose matters, and concentrated supplements deliver much higher doses than dietary sources.

3. Avoid the "natural means safe" assumption. Many naturally occurring compounds have potent physiological effects. "Natural" does not automatically mean safe during pregnancy. Evaluate each ingredient on its evidence, not its origin.

4. Disclose everything to your provider. Bring a complete list of every supplement you take — including brand names and doses — to your prenatal appointments. This allows your provider to evaluate potential interactions and make informed recommendations.

5. When in doubt, wait. If there isn't clear evidence that a supplement is safe during pregnancy, the prudent approach is to discontinue it until after pregnancy and breastfeeding, unless your provider specifically advises otherwise.

A Note About CHRY and Pregnancy

CHRY is formulated for general adult recovery and is not specifically designed, tested, or recommended for use during pregnancy or breastfeeding. While individual ingredients in CHRY (such as magnesium glycinate) have been studied in pregnancy contexts, the complete formula has not been evaluated for use during pregnancy. If you are pregnant, planning to become pregnant, or breastfeeding, please consult your obstetrician or healthcare provider before using CHRY or any dietary supplement.

The Bottom Line

Pregnancy is not the time for supplement experimentation. It's the time for evidence-based essentials, transparent conversations with your healthcare provider, and an abundance of caution. Some supplements — like folate and iron — have strong evidence and broad medical consensus supporting their use during pregnancy. Others require more individual evaluation. And for many, the honest answer is that we simply don't have enough data from human pregnancy studies to make confident safety claims. Your provider is your best resource for navigating these decisions.