What Does Heartleaf Do for Skin? The Science Behind Houttuynia Cordata

Christine Kang


If you've been paying attention to K-beauty over the last few years, you've probably noticed heartleaf showing up everywhere. What started as a traditional Korean herbal remedy — used for centuries in Korean, Japanese, and Chinese medicine — became one of the most talked-about skincare ingredients in 2019 when Korean beauty brands began centering entire product lines around it. But heartleaf isn't a trend ingredient. It's a botanically complex, research-backed plant with specific documented benefits for sensitive, eczema-prone, and reactive skin. At Treats Lab, Houttuynia Cordata is one of the four botanicals in our patented Bi-Om Complex™.

TL;DR

  • Heartleaf (Houttuynia cordata) is a flowering herb native to East Asia, used for centuries in Korean traditional medicine — known in Korean as 어성초 (Eoseongcho) and 십약 (sipyak), meaning "ten medicines"
  • Its active compounds are flavonoids — including quercetin, quercitrin, hyperoside, and rutin — with documented anti-inflammatory, antimicrobial, and antioxidant properties
  • Heartleaf has documented antimicrobial activity against Staphylococcus aureus — the bacterium most directly associated with atopic dermatitis flares
  • It inhibits pro-inflammatory cytokines TNF-α and IL-6, reducing the inflammatory signaling that drives redness, swelling, and itch in eczema-prone skin
  • Unlike synthetic antibiotics, heartleaf manages microbial populations without significantly disrupting the skin's beneficial resident microflora — supporting long-term microbiome health
  • It also functions as a humectant, drawing moisture into the skin and supporting hydration
  • Houttuynia Cordata is one of the four botanicals in the Bi-Om Complex™ in both Treats Lab formulas — chosen for its specific relevance to the microbiome and inflammatory dynamics of atopic skin
  • Most skin types tolerate heartleaf well — those with sulfonamide allergies or very reactive skin should patch test first

In This Article

  1. What Is Heartleaf and Where Does It Come From?
  2. What Are the Active Compounds in Houttuynia Cordata?
  3. What Does Heartleaf Do for the Skin?
  4. Why Is Heartleaf Particularly Relevant for Eczema-Prone Skin?
  5. Why Is Heartleaf in the Bi-Om Complex™?
  6. FAQs About Heartleaf for Skin


What Is Heartleaf and Where Does It Come From?

Heartleaf — scientifically known as Houttuynia cordata — is a perennial flowering herb native to East Asia, found throughout Korea, Japan, and China. It gets its English name from its small, dark green heart-shaped leaves. In spring it produces delicate white clover-like flowers.

In Korean it's called 어성초 (Eoseongcho) — which roughly translates to "fish smell herb," a reference to its distinctive pungent scent when fresh. It's also called 십약 (sipyak), meaning "ten medicines," because of the breadth of ailments it has been traditionally used to address. That name tells you something important about how Korean medicine has understood this plant — not as a single-purpose remedy but as a broadly therapeutic herb.

Heartleaf has been used in traditional Korean, Chinese, and Japanese medicine for centuries — as an anti-inflammatory, an antimicrobial, a digestive aid, and a topical treatment for skin conditions. It's also eaten as a leaf vegetable in some Asian cuisines, adding a slightly sour, herbal tang to dishes.

In modern skincare, heartleaf was a relatively obscure ingredient until 2019, when Korean brand ANUA launched its now-famous heartleaf toner and the ingredient went mainstream in the K-beauty world. Since then it has become one of the most studied and searched skincare botanicals — and for good reason. The traditional use is now being validated by modern research in ways that make heartleaf one of the most scientifically interesting ingredients in sensitive skin care.

Learn more about the ingredient: Heartleaf (Houttuynia Cordata)


What Are the Active Compounds in Houttuynia Cordata?

The therapeutic properties of heartleaf come primarily from its flavonoid content — a family of polyphenolic compounds with well-documented biological activity. The key flavonoids in Houttuynia cordata include:

Quercetin — one of the most studied flavonoids in dermatology, with documented anti-inflammatory, antioxidant, and antihistamine properties. Relevant to eczema specifically because of its ability to reduce histamine release and modulate the immune response.

Quercitrin — a quercetin glycoside with additional documented photoprotective properties, shown to reduce UVB-induced damage to skin cells. Also exhibits anti-inflammatory activity through inhibition of pro-inflammatory enzyme pathways.

Hyperoside — another quercetin glycoside with anti-inflammatory and antioxidant activity, specifically shown to inhibit the release of inflammatory mediators in the skin.

Rutin — a flavonoid glycoside that strengthens capillary walls, supports microcirculation, and has anti-inflammatory and antioxidant properties. Relevant to redness and reactive skin conditions.

Afzelin and Apigenin — additional flavonoids with documented antimicrobial and anti-inflammatory activity.

Together, this flavonoid profile gives Houttuynia cordata its broad therapeutic activity — anti-inflammatory, antimicrobial, antioxidant, and hydrating — through multiple simultaneous mechanisms rather than a single targeted action. This is part of what makes traditional herbal ingredients like heartleaf different from isolated synthetic actives. The complexity of the plant's chemistry produces effects that work together rather than in isolation.


What Does Heartleaf Do for the Skin?

Anti-inflammatory — calming redness and irritation
Heartleaf extract's flavonoids inhibit pro-inflammatory cytokines — specifically TNF-α and IL-6 — that drive the redness, swelling, and irritation associated with eczema, acne, and reactive skin conditions. By downregulating these inflammatory mediators, heartleaf helps calm the immune signaling that produces visible inflammation without suppressing the immune system entirely — a meaningful distinction from steroid-based approaches.

Learn more: How to Calm Itchy Skin Without Steroids

Antimicrobial — targeting S. aureus without disrupting the microbiome
This is the property most directly relevant to eczema-prone skin. Houttuynia cordata has documented inhibitory activity against Staphylococcus aureus — the bacterium found in up to 90% of atopic dermatitis skin during flares, producing toxins that directly trigger immune overreaction and itch. Importantly, heartleaf manages microbial populations without significantly disrupting the skin's beneficial resident microflora — supporting long-term microbiome health rather than creating the disruption that synthetic antimicrobials can cause.

Learn more: Atopic Dermatitis vs Seborrheic Dermatitis: Same Symptoms, Very Different Causes

Humectant — drawing moisture into the skin
Heartleaf functions as a humectant — attracting water molecules to the skin and supporting hydration from within the surface layers. This makes it particularly relevant for eczema-prone skin, which is characteristically dry and prone to transepidermal water loss due to barrier dysfunction. The hydrating effect of heartleaf works alongside its anti-inflammatory properties — supporting skin comfort while also addressing the dryness that makes reactive skin more vulnerable.

Learn more: Why Beta Glucan Is the New Hyaluronic Acid for Sensitive Skin

Antioxidant — protecting against environmental damage
The flavonoids in heartleaf — particularly quercetin and quercitrin — neutralize reactive oxygen species (ROS) generated by UV exposure and environmental stressors. This helps protect the skin's barrier proteins and collagen from oxidative damage, reducing the contribution of environmental factors to skin inflammation and aging.

Sebum regulation — relevant for combination and oily skin
Heartleaf has documented sebum-regulating properties, making it relevant not just for dry and eczema-prone skin but also for combination and oily skin types dealing with reactive conditions. This is part of why it has been so widely adopted in K-beauty — it's genuinely suitable for a broad range of skin types and concerns.


Why Is Heartleaf Particularly Relevant for Eczema-Prone Skin?

For atopic dermatitis specifically, heartleaf addresses several of the core dynamics driving the condition simultaneously.

The S. aureus connection. As we've covered in depth in our eczema content, Staphylococcus aureus overgrowth is one of the most well-established drivers of atopic dermatitis flares — found in lesional skin in up to 90% of people with the condition. S. aureus produces toxins that damage barrier proteins, trigger immune overreaction, and amplify the itch-scratch cycle. Heartleaf's documented antimicrobial activity against S. aureus makes it directly relevant to interrupting this dynamic. Houttuynia cordata inhibits the upregulation of pro-inflammatory cytokines triggered by S. aureus" — addressing both the microbial and inflammatory components simultaneously.

The barrier support connection. Research on Houttuynia cordata polysaccharides specifically has shown that heartleaf can help restore barrier proteins that are damaged by S. aureus toxins and inflammatory processes — reducing epidermal thickness, mast cell infiltration, and inflammatory cytokines while restoring barrier proteins in atopic dermatitis.

The microbiome-friendly antimicrobial advantage. One of the most important distinctions between heartleaf and conventional antimicrobial approaches is its selectivity. Unlike antibiotics, which disrupt the full microbial community of the skin — reducing beneficial bacteria alongside harmful ones — heartleaf manages S. aureus populations without significantly disrupting the skin's beneficial resident microflora. For eczema-prone skin, where microbial diversity is already compromised, maintaining the beneficial bacteria that help regulate immune response is critical. Heartleaf supports this balance rather than disrupting it further.

Learn more: 7 Types of Eczema: Microbiome Guide

One important nuance. Most skin types — including sensitive and eczema-prone — tolerate heartleaf well. However, individuals with allergies to sulfonamides (medicines used to treat bacterial infections) should exercise caution, as there is a potential for cross-reactivity. Very reactive skin should always patch test new ingredients, including heartleaf, before full application.


Why Is Heartleaf in the Bi-Om Complex™?

Houttuynia Cordata is one of the four botanicals in the patented Bi-Om Complex™ — alongside Coptis Japonica, Scutellaria Baicalensis, and Dictamnus Dasycarpus Root Extract — in both the ABC Microbiome Calming Lotion and the R+R Barrier Recovery Mist.

The reason heartleaf is in the complex rather than being used alone comes down to how these four botanicals work together. Korean medicine has long understood that combining herbs produces effects greater than any single ingredient — what modern research calls the "entourage effect." Each botanical in the Bi-Om Complex brings distinct antimicrobial and anti-inflammatory properties targeting different aspects of the inflammatory and microbial dynamics driving eczema-prone skin:

  • Houttuynia Cordata (Heartleaf) — antimicrobial against S. aureus, barrier protein restoration, anti-inflammatory via cytokine inhibition
  • Coptis Japonica — berberine-rich, antifungal against Malassezia, broad-spectrum antimicrobial
  • Scutellaria Baicalensis — baicalin and baicalein, anti-inflammatory and antifungal
  • Dictamnus Dasycarpus Root Extract — antimicrobial, antifungal, anti-inflammatory for intense itch conditions

Together, the Bi-Om Complex addresses both the bacterial dysbiosis of atopic dermatitis and the fungal dysbiosis of seborrheic dermatitis — making it relevant to multiple types of inflammatory skin conditions rather than just one.

Learn more: Atopic Dermatitis vs Seborrheic Dermatitis: Same Symptoms, Very Different Causes

Learn more: How to Support Your Skin Microbiome for Healthy, Balanced Skin


FAQs About Heartleaf for Skin

→ What is heartleaf in skincare?

Heartleaf is the common English name for Houttuynia cordata — a flowering herb native to East Asia that has been used in Korean, Chinese, and Japanese traditional medicine for centuries. In Korean skincare it's known as 어성초 (Eoseongcho). Its active compounds are flavonoids — including quercetin, hyperoside, and rutin — with documented anti-inflammatory, antimicrobial, antioxidant, and hydrating properties. It gained mainstream K-beauty popularity in 2019 and is now one of the most researched botanical ingredients for sensitive, eczema-prone, and reactive skin.

→ Is heartleaf good for eczema?

Yes — heartleaf has specific documented properties that are directly relevant to atopic dermatitis. It has antimicrobial activity against Staphylococcus aureus — the bacterium found in up to 90% of eczema-prone skin during flares — and inhibits the pro-inflammatory cytokines that S. aureus triggers. Research on Houttuynia cordata polysaccharides specifically showed reduced epidermal thickness, mast cell infiltration, and inflammatory cytokines alongside restored barrier proteins in atopic dermatitis models. Importantly, it achieves this without significantly disrupting the skin's beneficial microflora — supporting long-term microbiome health alongside its anti-inflammatory effects.

→ What is Houttuynia cordata used for in Korean medicine?

In Korean traditional medicine, Houttuynia cordata — called 십약 (sipyak), meaning "ten medicines" — has been used for a broad range of conditions including inflammatory skin conditions, digestive complaints, respiratory issues, and as a general anti-inflammatory and antimicrobial remedy. The name "ten medicines" reflects its broad therapeutic application rather than a single targeted use. For skin specifically, it was traditionally used for inflammatory and heat-pattern skin conditions — what Korean medicine would classify as damp heat presentations — which maps closely to what we now understand as atopic dermatitis and seborrheic dermatitis.

→ Is heartleaf the same as houttuynia cordata?

Yes — heartleaf is the common English name for Houttuynia cordata. It goes by several other names including fish mint, fish leaf, chameleon plant, and dokudami (in Japanese). In Korean it's 어성초 (Eoseongcho) or 십약 (sipyak). On skincare ingredient lists it appears as "Houttuynia Cordata Extract" — the INCI name used internationally.

→ Can heartleaf cause skin irritation?

Most skin types — including sensitive and eczema-prone — tolerate heartleaf well, and it is generally considered a low-irritation ingredient. However, individuals with known allergies to sulfonamides (a class of medicines used to treat bacterial infections) should exercise caution due to potential cross-reactivity. Some people with very reactive skin report mild tingling on first use. As with any new skincare ingredient, patch testing on a small area of skin before full application is always advisable — particularly for eczema-prone skin that may be in an active flare.

→ How does heartleaf compare to centella asiatica for sensitive skin?

Both heartleaf and centella asiatica are K-beauty botanicals with strong anti-inflammatory and soothing properties — and both are in Treats Lab formulas. The key difference is in their mechanisms. Centella asiatica — specifically its active compounds madecassoside and asiaticoside — is particularly known for barrier repair and wound healing. Heartleaf's primary strength is its antimicrobial activity against S. aureus and its cytokine-inhibiting anti-inflammatory mechanism. For eczema-prone skin, the two work complementarily — centella supporting barrier structure while heartleaf addresses the microbial and inflammatory dynamics. Together as part of the Bi-Om Complex™ and Full Spectrum Cica™ in the ABC Microbiome Calming Lotion, they provide more comprehensive support than either ingredient alone.

→ What skin types benefit most from heartleaf?

Heartleaf is particularly beneficial for sensitive, eczema-prone, acne-prone, and reactive skin — any skin type dealing with inflammation, microbial imbalance, or barrier compromise. Its humectant properties also make it useful for dry skin. Its sebum-regulating properties make it relevant for combination and oily skin prone to reactive conditions. It is one of the more broadly applicable botanical ingredients in K-beauty precisely because its flavonoid chemistry addresses multiple skin concerns simultaneously rather than targeting a single issue.

→ Is the heartleaf in ANUA products the same as in Treats Lab?

The ingredient — Houttuynia cordata extract — is the same plant source. However, the formulas are significantly different. ANUA's heartleaf products use heartleaf as the hero standalone ingredient. Treats Lab's formulas include Houttuynia Cordata as one of four botanicals in the patented Bi-Om Complex™ — a combination that our patent shows produces an entourage effect, with the four botanicals working together more effectively than any single ingredient alone. The broader formula context — including ceramides, beta-glucan, madecassoside, and Lactobacillus Ferment — also differs significantly, designed specifically for eczema-prone and sensitive skin rather than general sensitive skin care.


Heartleaf and the Bigger Picture

Houttuynia cordata is one of those ingredients that rewards closer attention. On the surface it looks like another K-beauty botanical riding a trend wave. But the research behind it — particularly its specific antimicrobial action against S. aureus and its ability to restore barrier function in atopic dermatitis models — points to something more substantive. Korean medicine knew about this plant's relevance to inflammatory skin conditions long before modern science had the tools to explain why. The Bi-Om Complex™ is built on that kind of accumulated wisdom — four botanicals that have stood the test of centuries of traditional use, now validated by the research that explains their mechanisms. Heartleaf is one of the most important pieces of that puzzle.

Learn more about the other Bi-Om Complex™ botanicals:
→ Coptis Japonica 
→ Scutellaria Baicalensis
→ Dictamnus Dasycarpus
→ How to Support Your Skin Microbiome for Healthy, Balanced Skin

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