What is Yerba Santa?

Yerba Santa (Eriodictyon californicum) is an aromatic evergreen shrub that grows across California, Oregon, Arizona, and northern Mexico. Its name means 'holy herb' in Spanish, reflecting the deep reverence Indigenous communities had for its healing power. The leaves are thick, sticky with resin, and pack a significant amount of beneficial plant compounds.

How does Yerba Santa work?

The active flavonoids in Yerba Santa — especially eriodictyol and homoeriodictyol — help open up airways by relaxing bronchial muscles, thin mucus so it moves more easily, and calm inflammation in the respiratory tract. Homoeriodictyol is also known to block bitter taste receptors, which is why it has long been used to mask the taste of bitter medicines. Sterubin, a more recently studied flavonoid in the plant, shows strong antioxidant and anti-inflammatory properties in laboratory research.

What forms does Yerba Santa come in?

Traditional preparation is as a strong leaf tea or tincture; these are the best-studied and most bioavailable forms. Capsules with dried leaf powder are convenient but slower acting. Syrups combine Yerba Santa with other respiratory herbs like mullein or licorice for palatability. Topical poultices of mashed leaves have traditionally been applied to bruises, sore muscles, and skin wounds.

Where it comes from:

Yerba Santa has one of the most well-documented Indigenous American herbalism histories in North America. Chumash, Pomo, Ohlone, Cahuilla, and many other California and Southwest nations used it for respiratory illness, fevers, rheumatism, and wounds for at least several centuries. Spanish missionaries learned of it from Indigenous healers and spread its use throughout colonial California. It was included in the U.S. National Formulary from 1894 to 1905 as an official expectorant remedy, and the FDA still lists homoeriodictyol as a generally recognized safe (GRAS) flavoring agent.

What does Yerba Santa help with?

• Congestion and mucus buildup: Yerba Santa acts as a natural expectorant, helping thin and loosen mucus in the airways so it can be cleared more easily. The resinous flavonoids in the leaf work directly on the bronchial lining to reduce sticky secretions and open up the breathing passages.
• Coughs and bronchitis: The herb helps calm irritated airways and reduce the frequency of dry, hacking coughs. Its anti-inflammatory compounds soothe the bronchial tubes, while its expectorant action helps clear the underlying mucus that triggers coughing fits.
• Seasonal allergies and hay fever: Eriodictyol and homoeriodictyol have demonstrated antihistamine-like effects in laboratory studies, helping to calm the immune overreaction that causes sneezing, runny nose, and itchy eyes. Many herbalists use it as a first-line botanical for allergy season, particularly for people whose allergies center on the sinuses and upper airway.
• Asthma (mild, supportive care): Traditionally used by Indigenous healers to ease wheezing and shortness of breath, Yerba Santa's bronchodilating flavonoids may help relax constricted airways. It is considered supportive care only and should not replace prescribed asthma medications.
• Sinus pressure and sinus infections: By thinning mucus and reducing inflammation in the sinus passages, Yerba Santa can relieve the pressure and stuffiness of sinus congestion. It has traditionally been used as a steam inhalation for sinus complaints as well as taken internally.
• Upper respiratory infections and colds: The herb's antimicrobial resins and immune-supporting flavonoids help the body fight off common respiratory bugs. It is most useful in the early stages of a cold or flu, when congestion and cough are just starting.
• Sore throat: Warm Yerba Santa tea coats and soothes an irritated throat while its anti-inflammatory compounds help calm swelling. Homoeriodictyol also subtly masks bitter and harsh sensations, making the throat feel more comfortable.
• Muscle and joint pain (topical): Crushed or heated Yerba Santa leaves applied directly to sore muscles, bruises, or inflamed joints have been used by Indigenous healers as an anti-inflammatory poultice. The resinous compounds are thought to penetrate the skin and reduce local inflammation.

What can Yerba Santa help prevent?

• Progression of upper respiratory infections when taken at early onset

Which foods are rich in Yerba Santa?

Yerba Santa is an herb not found in any common food source. To support the same respiratory and anti-inflammatory pathways it works on, focus on foods rich in related flavonoids: citrus fruits (naringenin, hesperidin), berries (quercetin, anthocyanins), onions and garlic (quercetin, allicin), and dark leafy greens. Warm broths and steam from hot liquids also mechanically support mucus clearance. Anti-inflammatory fats from olive oil and fatty fish complement Yerba Santa's airway-calming effects. Avoid dairy and refined sugar during active respiratory illness, as both may thicken mucus and dampen immune response.

What are the side effects of Yerba Santa?

• Skin irritation or contact dermatitis (topical use in sensitive individuals)
• Allergic reaction in people sensitive to related plants
• Mild stomach upset if taken in large amounts on an empty stomach
• Not recommended during pregnancy or breastfeeding (insufficient safety data)

Good to know:

Yerba Santa has a long history of safe use in traditional settings and is generally well tolerated in normal herbal doses. Pregnant and breastfeeding women should avoid it due to insufficient safety data. People with allergies to the Hydrophyllaceae plant family should use caution.

How much Yerba Santa should you take?

• Recommended daily: Tea: 1–2 teaspoons of dried leaf per 8 oz hot water, steeped 10–15 minutes, 2–3 times daily. Tincture (1:5): 2–4 mL (roughly 40–80 drops) up to 3 times daily. Capsules (dried herb): 300–500 mg, 2–3 times daily.
• Best time of day: Morning and midday are best for respiratory support to help clear airways throughout the day. Avoid large doses right before bed as the expectorant effect may loosen mucus and disrupt sleep.
• With or without food: Can be taken with or without food. Taking with a small meal may reduce any chance of stomach upset. Tea form is most effective on its own, sipped slowly while warm.
• Time to effect: Acute respiratory and congestion relief: 30–60 minutes. Sustained benefit for allergies or chronic respiratory conditions: 1–2 weeks of consistent use.
• How long to take it: For acute illness: use for the duration of symptoms (typically 5–10 days). For seasonal allergies: use throughout allergy season with a break afterward. For ongoing respiratory support: take for 4–6 weeks, then take a 2-week break before resuming. Long-term continuous use beyond 3 months has not been well studied.