Skip to content

The brain fog isn't in your head.

It's in four nutrients your brain depends on… and isn't getting enough of anymore. Here's what's actually happening
A middle-aged woman with blonde hair sits at a desk looking stressed, resting her head on her hand while staring at a laptop. Glasses, a pen, and a notebook are on the table in front of her.

You've probably been told it's menopause.

That this is what midlife looks like. That the word that won't come, the thread lost mid-meeting, the 3am wake-up and the foggy morning after — all of it is hormonal, and there's not much to do about it.

That's partly true and mostly incomplete.

Estrogen does real work in the brain — it helps neurons take in fuel, modulates serotonin and dopamine, and dampens inflammation. When it drops, those protections weaken. But what fills that gap is nutrition. And that's where most women, and most multivitamins, fall short.

How common is this, really?

  • 44 – 62%

    of women report cognitive decline in perimenopause.

    El Khoudary et al., 2019; Sullivan et al., 2001¹

  • 67%

    of affected women say it happens every day.

    Johnson & Ogden, 2025²

  • +31%

    higher odds of brain fog vs. premenopausal women.

    N = 14,234 · npj Women's Health, 2026³

Women reporting forgetfulness by menopause stage.

Your brain isn't failing. It's losing its building materials.

The brain runs on specific nutrients and signaling molecules. Estrogen had been helping the brain use them efficiently. When estrogen drops, what's left is what you can deliver through nutrition — and that's where the gap lives.

Nutrient
What it does in the brain
Why you're probably low

Vitamin B12

methylcobalamin

Vitamin B12

Maintains nerve insulation. Drives neurotransmitter synthesis. Supports oxygen delivery to the brain.

Absorption declines with age. Most supplements use cyanocobalamin — cheaper, less usable.

DHA

algae omega-3

DHA

Structural fat brain cells are built from. ~60% of the brain's dry weight is fat. Supports membrane fluidity and signaling.

ALA-to-DHA conversion runs at 1–10%. Algae is the only direct plant source.

Vitamin D3

from lichen

Vitamin D3

Signals directly to neurons. Supports mitochondrial energy. Reduces neuroinflammation.

42% of US adults are deficient. Most plant-based supplements still use D2 — significantly weaker.

Magnesium

absorbable form

Magnesium

Supports deep sleep — when the brain clears waste. Regulates excitatory neurotransmitters. Calms the stress response.

Most supplements use magnesium oxide — absorbs at roughly 4%. Soil depletion has reduced food sources.

Built around the cluster. In the forms the body absorbs.

COMPLEMENT® Essential delivers the four cognitive nutrients in the bioactive forms the brain actually uses. COMPLEMENT® ForHer adds iron — for women in perimenopause whose ferritin is quietly being drained — plus women-specific support for midlife biology.

  • A white and multicolored resealable pouch labeled Complement Essential with a list of nutrients like B12, D3, DHA/EPA, iodine, K2, zinc, magnesium, and selenium. Three black capsules are placed beside the pouch.
    COMPLEMENT® ESSENTIAL

    The foundation · Three capsules daily

    • Methylcobalamin B12 — 300 mcg
    • Vitamin D3 (lichen) — 2,000 IU
    • Magnesium — 200 mg
    • Kelp iodine — 150 mcg
    • L-selenomethionine — 50 mcg
    • Zinc picolinate — 8 mg
    • Vitamin K2
    • Algae DHA/EPA — 470 mg
  • A white and pastel-colored pouch labeled Complement ForHer with text about benefits for women, including energy, cognitive function, reproductive health, and immunity, sits beside several white capsules.
    COMPLEMENT® FORHER

    For perimenopause specifically · Pairs with Essential

    • Iron (bisglycinate chelate) - 9mg
    • Folate (liposomal (6S)-5-methyltetrahydrofolic Acid, glucosamine salt) - 600mcg
    • Boron (calcium fructoborate) - 1mg
    • Choline (phosphatidylcholine) - 110mg
    • Copper (copper chelate) - 0.7mg:
    • Inositol - 400mg:

    The bioavailable form — no constipation, no nausea common with standard iron supplements.

COMPLEMENT® ForHer Essential System

5.0
14+ Reviews

Science-backed health solution for women, combining the 8 essential nutrients for plant-based eaters, plus 6 vitamins and minerals to support longevity, vitality, and hormonal balance in women.

  • 100-day money-back guarantee
  • Free USA shipping over $95
  • Supports all-day energy.*
  • Promotes foundational health & longevity.*
  • Supports immune, heart, & brain health.*
  • Helps regulate normal metabolism.*
  • Essenced with peppermint.
  • Each batch is third-party tested and developed through our transparent production process.
  • 100% compostable pouch.

Ingredients

  • Iron (as Iron Bisglycinate Chelate) - 9mg:

Iron is an essential mineral needed for healthy red blood cells and oxygen transport, especially important for women of reproductive age due to their elevated needs.

  • Folate (A Liposomal (6S)-5-Methyltetrahydrofolic Acid, Glucosamine Salt) - 600mcg:

Folate is a vital B-vitamin necessary for DNA synthesis and cell function, commonly found in diets abundant with leafy greens or fortified foods.

  • Boron (as food-based, Calcium Fructoborate) - 1mg:

Boron is a trace mineral that supports bone health and metabolism, typically found in fruits, vegetables, and nuts, but not always consumed in adequate amounts.

  • Choline (as Phosphatidylcholine) - 110mg:

Choline is a crucial nutrient for brain and liver health, predominantly found in animal products, making it harder to obtain from a vegan diet.

  • Copper (as Copper Chelate) - 0.7mg:

Copper is an essential trace mineral important for various bodily functions, often less abundant in diets low in organ meats and shellfish.

  • Inositol - 400mg:

A B-vitamin compound supporting cellular health and signaling, commonly found in fruits, beans, grains, and nuts, but often under-consumed.

  • Vitamin K2 - 50 mcg:

K2 isn't available in plant-based foods except for natto, a Japanese fermented soy product (and it's not in tempeh), so those eating Western diets need to supplement in order to get it.

  • Vitamin D3 - 50 mcg:

We love nature and spending time outdoors. But we also wear clothing, and most of us work inside during daylight hours. That means our natural ability to soak up the sun's rays is limited, and as a result, many of us — regardless of dietary pattern — might be deficient in Vitamin D.

  • DHA/EPA Omega-3s - 450 mg:

Vegan food sources of Omega-3s like flax and chia seeds don’t provide two essential types — namely DHA and EPA. Seeds provide ALA Omega-3s, and are an amazing addition to your plate, but most people do not convert ALA into DHA and EPA.

  • Iodine - 450 mg:

Worldwide, iodine deficiency affects two billion people and is the leading preventable cause of intellectual and developmental disabilities. In plant foods, iodine is found inconsistently and depends on the iodine content of the soil. It’s possible to get enough iodine if you regularly eat seaweed (multiple times a week), or use iodized salt, but this is one essential nutrient that shouldn’t be overlooked whether you’re vegan or not.

  • Magnesium - 200 mg:

Soil depletion is a major cause of Magnesium deficiency in the overall population, and affects vegans as well as non-vegans.

  • Selenium - 50 mcg:

Our depleted soil may mean that plant foods, in general, do not contain enough Selenium (and that’s even true for some Brazil nuts).

  • Zinc - 8 mg:

Legumes and seeds are the best natural sources on a plant-based diets, but vegans who avoid those food groups, as well as those who are worried about its bioavailability can benefit from the addition of Zinc with Complement Essential.

  • Vitamin B12 - 300 mcg:

Soil bacteria produce Vitamin B12 — which is essential for humans in order to protect neutral health and reduce inflammation. But modern agriculture and other human behaviors decimate these bacterial colonies that produce B12.

HSA/FSA Eligible with

Truemed icon

We've partnered with Truemed to make COMPLEMENT® eligible for Health Savings Account (HSA) and Flexible Spending Account (FSA) spending. Simply take a short 2-minute survey after purchase to start the reimbursement process.

As seen on

200,000+ customers threw out their supplement drawer.

★★★★★

COMPLEMENT® ForHer + Essential

"I've been taking ForHer for about two weeks now and I feel like I'm sleeping better and starting to have a bit more energy."

— Verified buyer | 2 weeks

★★★★★

COMPLEMENT® ForHer + Essential

"After going plant based for a year and trying to fill any vitamin deficiency with tons of different capsules... I finally found the all in one supplement. I no longer worry if I am getting what I need."

— Verified buyer | 8 months

★★★★★

COMPLEMENT® ForHer + Essential

"Within a few months of taking Complement, I started noticing a ton of new hair growth... the hair thinning I had been experiencing quickly resolved."

— Verified buyer | 4 months

A hand holds a white and purple Complement For Her supplement pouch beside a larger Complement Essential supplement pouch. Both pouches list vitamins and nutrients. Three capsules and one white tablet are on the surface below.

You’re not losing your mind.

Your brain is losing its building materials. Essential + ForHer is the precision correction.

Dr. Joel Kahn, MD
co-formulated

200,000+
customers

100-day
guarantee

Frequently asked questions.

Still not sure? Find answers to your questions here.

What are the nutrition facts?

 

Nutrition Facts ForHer System

Are ForHer and Essential two different products?

The ForHer Essential System combines Complement Essential, containing the eight hard-to-get vitamins, minerals, and omega-3 fatty acids on a plant-based diet, with ForHer, six additional critical nutrients critical for female hormonal balance, cognitive function, and longevity.

ForHer is designed specifically to complement Essential, to create a complete science-backed solution to help you feel your best, most vibrant self daily.

I already take Essential, should I add ForHer?

Complement Essential was formulated to provide the missing or hard-to-get nutrients in a plant-based diet.

ForHer is a collection of essential nutrients not included in Essential. While these nutrients may not be missing from a plant-based diet, many plant-forward women may benefit from adding the additional dosages.

ForHer is designed to support hormonal balance, cognitive function, and longevity in women, and intended to be taken in addition to Complement Essential or another multivitamin.*

Are ForHer and Essential vegan?

Yes, all Complement nutrients are 100% vegan and cruelty-free. (And so are we.) All of the ingredients are sourced from plants, bacteria, minerals or algae.

Do Complement Essential or ForHer contain soy, nuts, gluten, GMO's or artificial ingredients?

Complement Essential and ForHer DO NOT CONTAIN: Soy, nuts, yeast, gluten, MSG, genetically modified organisms, artificial colors or flavors, fish, dairy, eggs or other animal-sourced ingredients.

Who is behind Complement?

We’re a team of nutrition-first individuals with unique health stories and backgrounds. Together, we're on a mission to support anyone looking to live a healthier life by ensuring they have the nutrients and information they need to thrive. Through sourcing the highest quality ingredients and fully transparent production, we leave absolutely nothing on the table when it comes to developing essential, premium plant-based nutrition products.

Why did you make the Complement Essential capsules black?

The unprocessed and unrefined oil used in Complement Essential naturally contains other beneficial compounds including carotenoids, Omega-7, and Chlorophyll — which gives it a dark green color that appears nearly black.

What is the suggested use?

For adults and children over 12, take 3 Complement Essential and 2 ForHer vegan capsules daily, preferably with a meal. Store in a cool, dark place.

Can my children take the Complement Essential ForHer System?

We formulated Complement Essential for adults and kids over 12. If you wish to give it to younger children, please consult with your doctor or pediatrician and show them the full ingredients list to determine its suitability and dose.

Can I take Complement Essential together with my other supplements or multivitamin?

Complement Essential, together with a whole-food, plant-based diet, will provide you with the nutrients you need to thrive. Formulated for optimal nutrient intake, Complement Essential is safe and non-toxic when taken as directed. If you take another supplement that contains any of the nutrients found in Complement Essential, you may exceed the tolerable upper intake for that nutrient. Speak with your doctor if you have any questions about how Complement Essential works with any other supplements or medications you are taking.

When can I expect my order?

We aim to ship orders within 24 hours of purchase. Our goal is to get Complement in your hands in just a few days!

A person holds a bag of Complement ForHer supplements in focus, with a young child in their other arm and a kitchen setting in the blurred background. A smiling woman holds a pouch labeled Complement Essential, a science-backed multinutrient for plant-based diets, listing nutrients like B12, D3, DHA/EPA, iodine, K2, zinc, magnesium, and selenium. A person holds a packet labeled Complement ForHer with benefits like energy, cognitive function, reproductive health, and immunity listed. The background is softly blurred, showing another person and indoor lighting. A woman with blonde hair stands in a modern kitchen, smiling while holding a packet labeled Complement Essential in front of her face, partially covering it. Bananas and kitchen utensils are visible in the background.
4.86
2443 reviews

Loved by thousands.

Customer Reviews

Based on 2443 reviews
91%
(2233)
5%
(130)
2%
(53)
0%
(11)
1%
(16)
K
Katherine M. (Hesperia, US)
Everything I Need!

I love how easy Essential makes getting in what I need! Tastes good and feels good!

B
Blane (Interlochen, US)
Trustworthy and Work Great!

I love Complement and fully trust them to provide the nutrients I am missing in my diet. Highly recommend for someone on a plant based diet or anyone lacking these important nutrients in their diet.

K
Kelly

I love this product and feel so good knowing I’m getting all my nutrients every day that i may be missing as a plant based eater. The only thing I don’t like is the timing of of the auto-ship. There is a 5-7 day gap from when I take my last capsules until I receive my next shipment leaving me taking other supplements to keep up my daily Vit D and B12. I wish it could ship sooner so that there is no gap.

E
Eve E. (Madison, US)
Essential is essential

I particularly like that it has what we need if we are gradually becoming more and more plant-centric in our eating. The algae-based omega 3 fatty acid blend does not cause fish-tasing burps the way that fish oil does.

C
Catherine S. (Norcross, US)
Just Got My Labs

I'm turning 40 next year and decided to finally go get blood work done. I eat a plant based diet and have been taking Essential INCONSISTENTLY for a solid year. My B12 was still healthy (although on the low end). That was the motivation I needed to dedicate myself to taking it consistently everyday. Imagine how well-off I will be with consistent use! I am a moderate/heavy exerciser, so getting in the proper nutrients is important to me so I can keep up my energy to stay youthful as long as I can, cand have fun doing so! It took some time, but it is now clear to me that taking Essential is, in fact, essential for me!

Science-backed sources.

Dig into the evidence...

Sources

  1. El Khoudary et al., 2019; Sullivan et al., 2001
  2. 
Johnson & Ogden, 2025

  3. N = 14,234 · npj Women’s Health, 2026
A white circle with a teal outline contains bold black text that reads 100-Day Money-Back Guarantee on a plain light background.

100% Happy

We stand behind our products 100%. If you’re not happy with the results, taste, or experience, we’ll fix it.

100-Day Guarantee

You have a full 100 days after receiving your product to try it out and see if it’s the right fit for you.

100% Money-Back

And if you don’t love it within the first 100 days, we’ll issue a full refund. No questions asked. No fine print. That’s the COMPLEMENT® guarantee.

{"statementLink":"","footerHtml":" ","consistentHelpData":[],"hideMobile":false,"hideTrigger":false,"disableBgProcess":false,"language":"en","position":"left","leadColor":"#2f6daa","triggerColor":"#2f6daa","triggerRadius":"50%","triggerPositionX":"left","triggerPositionY":"bottom","triggerIcon":"people","triggerSize":"small","triggerOffsetX":20,"triggerOffsetY":20,"mobile":{"triggerSize":"small","triggerPositionX":"left","triggerPositionY":"bottom","triggerOffsetX":3,"triggerOffsetY":20,"triggerRadius":"50%"}}