Chlorella powder in bowlShare on Pinterest
Nadine Greeff/Stocksy United

Pregnant? You’re probably wondering which supplements you can continue taking during your pregnancy. And if you’re not normally a supplement person, you may be curious whether certain ones might help support you and your baby over the next 9 months.

Chlorella is a green, single-celled, freshwater alga that’s similar to spirulina. It’s touted for its high concentration of vitamins and minerals, as well as its detoxifying properties, among other potential benefits.

Can you take chlorella during pregnancy? Maybe. Here’s what you need to know about this popular supplement, the research behind it, and its safety for you and your baby.

Just 2 teaspoons of chlorella powder contain a whopping 2,920 international units (IUs) of vitamin A, or 60 percent of the Daily Value (DV) of this vitamin. Other notable nutrients include 12 milligrams of iron (70 percent of the DV) and 15 micrograms of vitamin B12 (250 percent of the DV).

Beyond the nutritional stats, chlorella may have particular benefits when it comes to pregnancy. Claims about the superfood surround anything from preventing anemia, which can crop up during pregnancy, to lessening swelling and edema in the hands and feet.

Some sites and supplement companies encourage people to take the supplement to “detoxify” their bodies from heavy metals and other toxins before trying to conceive. There are also claims that chlorella can help ward off pregnancy-related hypertension.

Katie Wells, founder of the blog Wellness Mama, shares that chlorella may also support the immune system.

Other potential benefits of chlorella include the following:

  • regulate blood sugar
  • lower cholesterol
  • fight free radicals (antioxidant properties)
  • lower blood pressure
  • support respiratory health
  • improve aerobic endurance

It’s important to note that there are over 30 varieties of chlorella. Most of the related research has focused on two main types — Chlorella vulgaris and Chlorella pyrenoidosa.

One study on Chlorella pyrenoidosa and pregnancy found that supplementation significantly reduces the risk of certain conditions, including anemia, protein in the urine (proteinuria), and swelling (edema).

Plus, the researchers stated that chlorella can give women a helpful boost of folate, vitamin B12, and iron — all of which are key to a healthy pregnancy. For reference, the women in the study were given 6 grams daily from their 12th to 18th week of pregnancy until they gave birth.

Another study in pregnant mice showed that supplementation with chlorella powder lowered levels of mercury transferred from mothers to their babies through the placenta.

What’s more, the mice had lower levels of mercury in their brain tissue, compared with those in the control group. This research speaks to the purported detoxification properties of the supplement.

Unfortunately, there’s no definitive information to suggest that taking chlorella is safe (or unsafe, for that matter) during pregnancy.

That said, studies have shown benefits without major side effects or risks. Keep in mind, though, that the sample sizes were relatively small, and some of these studies were conducted in animals — not humans.

Be sure to discuss any new supplements with your healthcare provider before starting them, especially if you’re pregnant.

If you choose to supplement with chlorella, you may find it in four main forms. Below are some examples:

Based on the number of product reviews, the capsule, tablet, and powder forms seem to be more popular than the tincture form.

No matter what type you choose, ask your OB-GYN how much you should take. You may experience unpleasant side effects if you take too much too soon.

Again, you should always speak with your OB-GYN before adding any new supplements to your routine during pregnancy. Chlorella may be safe, but more research is needed before it’s broadly recommended.

In particular, chlorella may pose some risks for those with an iodine allergy or sensitivity, as well as people with autoimmune disorders.

Furthermore, due to its high vitamin K content, it may also inhibit the effects of blood-thinning medications like warfarin. Nevertheless, warfarin is contraindicated in pregnancy, so most pregnant people will have stopped taking it or changed to another therapy while pregnant.

Finally, the Food and Drug Administration doesn’t regulate dietary supplements as closely as it regulates prescription drugs, so read labels carefully to ensure there aren’t any added ingredients you may have interactions with.

Side effects

You may experience some side effects while adding chlorella to your routine. These include stomach issues, specifically abdominal discomfort and nausea.

However, these symptoms may be rare. In a study on the supplement, only one of the 150 participants reported side effects severe enough to withdraw.

One Japanese study on chlorella and breastfeeding found that chlorella reduced the dioxin concentration of breast milk by as much as 30 percent. Dioxins are the result of persistent environmental pollutants and may be highly toxic to humans.

When dioxins collect in the body they may cause health issues like cancer, hormonal imbalances, and immune system dysfunction.

Moreover, taking chlorella may be a good way to support your increased nutritional demands during breastfeeding.

Regarding its safety while breastfeeding, manufacturers say it’s OK, and studies haven’t brought up any major red flags. Still, as is the case with its use during pregnancy, you should check with your or your child’s healthcare provider before stocking up.

Speak with your OB-GYN to see whether supplementing with chlorella may be a good choice for you. While the claims are quite enticing, more research is needed on using this supplement while you’re pregnant or breastfeeding.

You can also support a healthy pregnancy by eating a well-balanced diet full of protein and veggies, drinking 10 cups of fluids each day, and getting around 30 minutes of moderate intensity exercise most days of the week. And be sure to keep up with your scheduled prenatal appointments.