Oligomannate: Seaweed / Brown Algae Extract to Treat Alzheimer’s & Dementia Symptoms

Last Updated: July 11, 2021


A drug made from seaweed may be able to help symptoms of dementia. It’s called Oligomannate, and clinical trials have given researchers hope that it helps relieve the thinking and memory problems that are so prevalent for our loved ones suffering with Alzheimer’s. Oligomannate has been available in China since 2019, and is working its way through the process of coming to Americans.

This is a big deal! In almost 20 years, pharmaceutical companies have started hundreds of clinical trials looking for a compound that could alleviate, or even cure, dementia.The only drug to receive FDA approval since 2003 was aducanumab (brand name Aduhelm), in June 2021, and Oligomannate has a chance at being only the second new Alzheimer’s drug since since Namenda in 2003.

The Chinese pharmaceutical company Shanghai Green Valley released Oligomannate to Chinese residents after years of testing, and phase 3 clinical trials in the U.S. beginning in 2021 could lead to availability here.

So, what is Oligomannate?


What is Oligomannate?

Oligomannate is made of extracts from brown algae. Put another way, it’s sugar derived from seaweed or kelp. (Seaweed looks like a plant, but is actually algae.) Shanghai Green Valley says the drug changes bacteria in our intestines in a way that decreases swelling in the brain. This makes Oligommanate different from another medication that recently received approval from the Food and Drug Administration—aducanumab (brand name Aduhelm)—which targets the amyloid-beta plaques believed to cause cell death in the brains of people with Alzheimer’s. Almost all other dementia drugs being tested in clinical trials, in fact, are designed to target amyloid-beta.

Researchers tested Oligomannate in pill form in double-blind, placebo-controlled trials. That means groups with dementia were given either the Oligomannate drug or a placebo (which is like a sugar pill, something with no actual benefit). What they found is that the group that took the algae extract showed a statistical improvement in cognitive function, or thinking ability. This improvement was shown after only four weeks in some subjects, and continued over follow-up assessments.


How Does Oligomannate Work?

Scientists have long believed there is a link between gut bacteria and the brain. Within our intestines are germs (metabolites) which serve purposes including keeping our immune systems strong. In people with Alzheimer’s disease, the gut bacteria changes to produce harmful cells that affect swelling in the brain. The dementia-causing proteins called amyloid-beta and tau increase in the brains of people with this gut-bacteria issue.

Oligomannate was shown, first in laboratory mice, to block the rise in harmful intestinal bacteria, reducing the buildup of proteins that cause swelling in the brain and bring symptoms like memory loss. Shanghai Green Valley Pharmaceuticals has said that in its clinical trials between 2014 and 2018, 818 test subjects were given either Oligomannate or a placebo for 36 weeks, and those who received the drug scored higher on tests of thinking ability and memory. Those improvements were shown in as little as four weeks.


For Which of Stages of Dementia is Oligomannate Effective?

The drug showed benefits for people with mild-to-moderate Alzheimer’s. This means someone in the later stages of dementia probably won’t see a benefit to taking Oligomannate, but people in the earlier and middle stages could see their symptoms improve.


How Much Will Oligomannate Cost?

The pill available in China is 150 milligrams and costs the equivalent of about $500 for one month’s supply. Because the drug is not yet available outside China, an issue like insurance coverage can’t be addressed yet. Medicare Part D, which covers prescriptions, and Medicare Advantage, which partners with private insurers and is tailored to specific individuals, can cover the cost of other Alzheimer’s drugs like memantine and cholinesterase inhibitors, so it is possible that if/when Oligomannate becomes available globally, these Medicare programs will cover costs for your loved one to try the new medicine.


Oligomannate Clinical Trials in the U.S.

Clinical trials are underway in the U.S., as Oligomannate moves closer toward approval from the FDA. Shanghai Green Valley is currently in Phase 3 here, recruiting more than 2,000 participants with mild to moderate Alzheimer’s for its study of the effectiveness of Oligomannate. The study began in 2020 but was still recruiting in June 2021, and anyone interested can get information at this link. Right now in the United States, participating in these trials is the only way to get Oligomannate, though there might be an alternative supplement that works in a similar way (see below).

The study is expected to conclude in 2026. FDA approval, if everything goes well, usually takes another 6 to 10 months at least, so Oligomannate probably won’t be available to people with Alzheimer’s in the U.S. until 2027.


Side Effects of Oligomannate

There are no reported side effects of Oligomannate. This doesn’t mean the drug is completely safe, but reporting on Oligomannate says side effects were similar to a placebo. One of the reasons more trials are required before the drug becomes widely available is that researchers must determine exactly which side effects people will experience if they start taking the drug. It’s possible longer-term issues simply haven’t surfaced yet. In fact, some skeptics have argued that the clinical trials so far have been too short to evaluate the medium- to long-term effects, including side effects.


Is There A Supplement Alternative to Oligomannate?

Is there a supplement alternative to Oligomannate? Maybe. Brown algae, brown seaweed, and kelp supplements are available to take as pills, drops, or powder to add to food or beverages. These are marketed as nutritious and useful in digestion, but the supplement market is notorious for loose regulations. Try to purchase supplements from a source you can trust, and have realistic expectations. Supplements are not pharmaceuticals, so the benefits of taking straight brown seaweed in pill form may not match the drug Oligomannate, even if the drug is made from brown seaweed extract.  More on dementia supplements.