Gigartina

BotanicalSeaweed

What is it

Gigartina is a genus of red marine algae. Several species (G. skottsbergii, G. chamissoi, G. papillata) are used in supplements as a source of sulfated polysaccharides (carrageenan-like compounds) marketed for antiviral support.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Antiviral support (research stage)

Limited Evidence

In vitro and small topical trials suggest activity against HSV, HPV; human oral efficacy is unproven.

How it works

Sulfated polysaccharides from gigartina (and other red algae) inhibit viral attachment to host cells in vitro, especially against HSV-1, HSV-2, HPV, and HIV. Cell-culture data have been promising but human clinical evidence is very limited. Some topical/intravaginal carrageenan products have been studied for HPV prevention with mixed results.

Dosage

No established human supplement dose. Topical/intravaginal carrageenan products have been studied at 0.5-1% concentrations.

When and how to take it

Follow product-specific instructions.

1 commercial form

Compare the main delivery options and what they’re best suited for.

Gigartina extract capsule

Specialty antiviral product.

Provides sulfated polysaccharides.

Safety

Oral safety data are limited. Carrageenan in food has GRAS status but degraded (poligeenan) forms can be inflammatory. Some research raises concerns about high-dose oral food-grade carrageenan and gut inflammation; the evidence is debated.

Who should be cautious

IBD or sensitive gut: limit oral carrageenan products. Pregnancy: limited data; use only with medical advice.

Interactions

No significant drug interactions reported.

Food sources

Red marine algae (rare in cuisine)

Amount
small amounts
%DV
—

Frequently asked questions

Does gigartina treat herpes?⌄

In vitro evidence is interesting but human clinical efficacy is unproven.

Is it safe to take long-term?⌄

Long-term oral safety is not well established. Use cautiously.

References

Gigartina on Wikidata — Wikidata link

Gigartina on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Gigartina (PubMed search) — PubMed link

Track Gigartina with Pilora

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.