Omega-3 Without the Mercury: Why Algae-Based Supplements Are a Great Choice for Pregnancy
When I started looking into how to naturally boost my fertility, I quickly realized that what I ate played a huge role. I wanted to nourish my body in the best way possible—giving my future baby the strongest start while also supporting my health. That’s when I learned how essential omega-3 is for fertility. It helps improve egg quality, supports implantation, and reduces inflammation—all things that can make a real difference when trying to conceive.
Living in Portugal, I had no shortage of grilled sardines, but let’s be honest—I wasn’t eating them nearly enough to get the recommended amount of omega-3 every week. Around the same time, I was deep into the Fertility & Pregnancy module at my INN studies, learning which foods truly support conception and which ones come with hidden risks—like fish that contain high levels of mercury. That made me wonder: if some fish are off-limits due to mercury, how safe is my omega-3 supplement?
So, I started researching. What I found surprised me: most fish oil supplements also contain traces of mercury and other contaminants. That’s when I discovered a cleaner, safer alternative—vegan omega-3 from algae. Fish get their omega-3 from algae in the first place, so why not go straight to the source?
Let’s break it all down—why omega-3 is so important when trying to conceive, the safest sources to get it from, and how to make sure you're choosing the right supplement.
Why Is Omega-3 Important for Pregnancy?
Before we get into algae supplements, let’s quickly talk about why omega-3 matters:
Baby’s Brain & Eye Development: DHA is crucial for your baby’s rapidly growing brain—especially in the third trimester when it’s growing at lightning speed. Interestingly, algae-based omega-3, specifically DHA, is just as effective as the fish-derived version in raising omega-3 levels in the body.
Hormone Balance & Fertility: Omega-3 supports reproductive health and helps with hormone balance, which is important when trying to conceive.
Mood Support for Mom: Research suggests omega-3 may help lower the risk of postpartum depression and support overall mental well-being.
What’s the Concern with Fish?
Fish is a fantastic natural source of omega-3, but some types contain methylmercury, a heavy metal that can be harmful in high amounts. While many experts agree that the benefits of eating low-mercury fish outweigh the risks, it’s understandable if you want to play it extra safe—especially during pregnancy.
The official recommendation is to limit high-mercury fish (like tuna, swordfish, and shark) and stick to safer options like sardines, mackerel, and anchovies. But if you’re not a big seafood eater, or if the thought of fish makes your pregnancy nausea worse (been there!), algae-based omega-3 supplements are a great alternative.
Why Algae-Based Omega-3?
Fish don’t magically produce omega-3 on their own—they get it from eating algae. So why not go straight to the source? Algae-based omega-3 supplements offer:
✅ A direct, plant-based source of DHA and EPA (the two most important omega-3s for pregnancy).
✅ No risk of mercury contamination—since algae are at the bottom of the food chain, they don’t accumulate heavy metals like fish do.
✅ An easy way to meet your omega-3 needs without having to track which fish is safe to eat this week.
Sustainability is another key reason algae omega-3 is gaining attention. Algae can be cultivated in controlled environments, reducing the environmental impact often associated with overfishing. Plus, algae is an abundant and renewable resource that doesn't require the same level of ocean resources as fish-based omega-3 production.
Are Algae Supplements as Effective as Fish-Based Omega-3s?
Short answer: Yes!
Longer answer: Studies show that algae-derived DHA is just as effective as fish-based DHA in raising omega-3 levels in the body. However, some algae supplements contain only DHA, while fish oil provides both DHA and EPA. Since EPA also plays a role in reducing inflammation and supporting heart health, you might want to check if your algae supplement includes both.
How to Choose a Good Algae-Based Omega-3 Supplement
Not all supplements are created equal, so here’s what to look for:
Third-Party Testing – Look for brands that test for purity, heavy metals, and contaminants.
DHA & EPA Content – Aim for at least 200-300mg of DHA per day during pregnancy. Some supplements also contain EPA for additional benefits.
No Fillers or Additives – Choose supplements with minimal added ingredients.
My Experience with Algae-Based Omega-3
Personally, I found algae-based omega-3 to be an easy and stress-free way to get my DHA. I wasn’t always in the mood for fish (pregnancy cravings are weird), so having a reliable supplement made things simpler. Plus, no fishy aftertaste—huge bonus!
Final Thoughts: Should You Choose Algae-Based Omega-3?
If you eat plenty of low-mercury fish, you might not need a supplement. But if you’re vegetarian, vegan or don’t love fish, or just want a worry-free omega-3 source, algae-based supplements are a fantastic option.
As always, check with your doctor or midwife before starting any new supplement to make sure it’s the right fit for you. Every pregnancy is different, and what works for one person might not be the best choice for another.
Now that we’ve covered supplements, what about fish? If you do want to include fish in your diet but aren’t sure which ones are safe, check out my guide on choosing the best pregnancy-safe fish [link to next article].
Why Algae-Based Omega-3?
Fish don’t magically produce omega-3 on their own—they get it from eating algae. So why not go straight to the source? Algae-based omega-3 supplements offer: ✅ A direct, plant-based source of DHA and EPA (the two most important omega-3s for pregnancy). ✅ No risk of mercury contamination—since algae are at the bottom of the food chain, they don’t accumulate heavy metals like fish do. ✅ An easy way to meet your omega-3 needs without having to track which fish is safe to eat this week.
Are Algae Supplements as Effective as Fish-Based Omega-3s?
Short answer: Yes!
Longer answer: Studies show that algae-derived DHA is just as effective as fish-based DHA in raising omega-3 levels in the body. However, some algae supplements contain only DHA, while fish oil provides both DHA and EPA. Since EPA also plays a role in reducing inflammation and supporting heart health, you might want to check if your algae supplement includes both.
How to Choose a Good Algae-Based Omega-3 Supplement
Not all supplements are created equal, so here’s what to look for:
Third-Party Testing – Look for brands that test for purity, heavy metals, and contaminants.
DHA & EPA Content – Aim for at least 200-300mg of DHA per day during pregnancy. Some supplements also contain EPA for additional benefits.
No Fillers or Additives – Choose supplements with minimal added ingredients.
My Experience with Algae-Based Omega-3
Personally, I found algae-based omega-3 to be an easy and stress-free way to get my DHA. I wasn’t always in the mood for fish (pregnancy cravings are weird), so having a reliable supplement made things simpler. Plus, no fishy aftertaste—huge bonus!
Final Thoughts: Should You Choose Algae-Based Omega-3?
If you eat plenty of low-mercury fish, you might not need a supplement. But if you’re vegetarian, vegan or don’t love fish, or just want a worry-free omega-3 source, algae-based supplements are a fantastic option.
As always, check with your doctor or midwife before starting any new supplement to make sure it’s the right fit for you. Every pregnancy is different, and what works for one person might not be the best choice for another.
Now that we’ve covered supplements, what about fish? If you do want to include fish in your diet but aren’t sure which ones are safe, check out my guide on choosing the best pregnancy-safe fish
Sources:
National Institutes of Health (NIH) - Omega-3 Fatty Acids
NIH Omega-3 Fatty AcidsHarvard T.H. Chan School of Public Health - Omega-3 Fatty Acids
Harvard T.H. Chan Omega-3DSM-fermenich - Busting the myths around algal-based omega-3s and their potential in early life nutrition
