Oil of Oregano by GNC Herbal Plus

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Dyspepsia. Oral olive leaf extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small study in healthy adults shows that taking a specific combination product containing olive leaf extract 24% and prickly pear cactus 33% (Mucosave, Bionap S.R.L.) 400 mg daily for 8 weeks seems to improve dyspepsia and other gastrointestinal symptoms when compared with placebo (105904). It is unclear if this benefit would occur in patients with clinically diagnosed dyspepsia.
• Exercise-induced respiratory infections. It is unclear if oral olive leaf extract is beneficial for reducing respiratory infections from exercise. Details: A small clinical study in high school athletes shows that taking one tablet of olive leaf extract providing eleuropein 100 mg daily for 2 months during training season does not reduce the incidence of the common cold when compared with placebo. While it may reduce the number of sick days by 28%, a sub-group analysis suggests that this reduction is only evident in female athletes (101860).
• Gastroesophageal reflux disease (GERD). Although there is interest in using oral olive leaf for GERD, there is insufficient reliable information about the clinical effects of olive for this condition.
• Herpes zoster (shingles). Although there is interest in using oral olive leaf for shingles, there is insufficient reliable information about the clinical effects of olive for this condition.
• Influenza. Although there is interest in using oral olive leaf for influenza, there is insufficient reliable information about the clinical effects of olive for this condition.
• Metabolic syndrome. It is unclear if oral olive leaf extract is beneficial for improving body composition and cardiovascular risk factors in patients with metabolic syndrome. Details: A small clinical trial in overweight, middle-aged males at risk for metabolic syndrome shows that taking four capsules of olive leaf extract providing oleuropein 51.1 mg and hydroxytyrosol 9.7 mg daily for 12 weeks improves insulin sensitivity by 15% when compared with placebo. However, body composition, blood pressure, cholesterol levels, and other cardiovascular risk factors were not improved (92245).
• Osteoarthritis. It is unclear if oral olive fruit or leaf extract is beneficial for improving osteoarthritis. Details: Preliminary clinical research shows that taking a freeze-dried aqueous extract of olive fruit 400 mg daily for 8 weeks decreases pain and increases mobility in people with osteoarthritis (14844). Other preliminary clinical research in adults with knee osteoarthritis shows that taking olive leaf extract 50.1 mg daily for 4 weeks improves overall pain measurements by 14%, compared to only 4% in the placebo group. However, many individual measurements of pain are not improved (92252).
• Osteoporosis. It is unclear if oral olive leaf extract is beneficial for osteoporosis. Details: Clinical research shows that taking olive leaf extract (Bonolive, BioActor BV) 250 mg daily for 12 months, along with elemental calcium 400 mg daily, increases osteocalcin levels by about 32% when compared to baseline; this increase was significant when compared to those taking calcium 400 mg plus placebo, who showed a 6% decrease in osteocalcin levels. However, taking olive leaf extract does not significantly increase bone mineral density of the lumbar spine or femur neck when compared with placebo (92247).
• Rheumatoid arthritis (RA). It is unclear if oral olive fruit extract is beneficial for improving RA symptoms. Details: Preliminary clinical research in adults with RA shows that taking an aqueous freeze-dried extract of olive fruit 400 mg daily for 8 weeks does not improve symptoms when compared with control (14844). More evidence is needed to rate the effectiveness of olive for these uses.

(Read more about OLIVE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there has been interest in using topical oregano oil for acne, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Asthma. Although there has been interest in using oral oregano for asthma, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Bronchitis. Although there has been interest in using oral oregano for bronchitis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Canker sores. Although there has been interest in using topical oregano oil for canker sores, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Cough. Although there has been interest in using oral oregano for cough, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Dandruff. Although there has been interest in using topical oregano oil for dandruff, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Diabetes. Although there has been interest in using oral oregano for diabetes, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Dysmenorrhea. Although there has been interest in using oral oregano for dysmenorrhea, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Dyspepsia. Although there has been interest in using oral oregano for dyspepsia, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Gingivitis. Although there has been interest in using topical oregano oil for gingivitis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Headache. Although there has been interest in using topical oregano oil for headache, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Insect repellent. Although there has been interest in using topical oregano oil as an insect repellent, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Intestinal parasite infection. It is unclear if oral oregano is beneficial in patients with intestinal parasite infections. Details: In one small, uncontrolled study, taking a specific emulsified oregano leaf oil product (ADP, Biotics Research Corporation) 200 mg orally three times daily with meals for 6 weeks resulted in eradication of Blastocystis hominis, Entamoeba hartmanni, and Endolimax nana from the stool in 10 of 13 patients (6878). The clinical significance of this is unclear since the Centers for Disease Control (CDC) considers Entamoeba hartmanni and Endolimax nana to be non-pathogenic, while blastocystosis caused by Blastocystis hominis is usually self-limiting and does not require treatment.
• Pain (acute). Although there has been interest in using topical oregano oil for the relief of acute pain, including joint and muscle pain, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Psoriasis. Although there has been interest in using topical oregano oil for psoriasis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Rhinosinusitis. Although there has been interest in using oral oregano for rhinosinusitis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Seborrheic dermatitis. Although there has been interest in using topical oregano oil for seborrheic dermatitis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Tinea capitis. Although there has been interest in using topical oregano oil for tinea capitis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Tinea corporis. Although there has been interest in using topical oregano oil for tinea corporis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Tinea pedis. Although there has been interest in using topical oregano oil for tinea pedis, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Toothache. Although there has been interest in using topical oregano oil for toothache, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Upper respiratory tract infection (URTI). Although there has been interest in using oral oregano for URTIs, such as the common cold and influenza, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Urinary tract infections (UTIs). Although there has been interest in using oral oregano for UTIs, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Varicose veins. Although there has been interest in using topical oregano oil for varicose veins, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Warts. Although there has been interest in using topical oregano oil for warts, there is insufficient reliable information about the clinical effects of oregano for this purpose.
• Wound healing. It is unclear if topical oregano is beneficial for improving healing or preventing infections in people with skin wounds. Details: One small clinical trial shows that applying an ointment containing a 3% concentration of the water-soluble fraction of the oregano plant twice daily for 10-14 days after minor dermatological surgery might reduce infection rates and improve scar formation when compared with petrolatum ointment (67348). More evidence is needed to rate oregano for these uses.

(Read more about OREGANO)

LIKELY SAFE ...when olive fruit is used orally and appropriately in amounts commonly found in foods.

POSSIBLY SAFE ...when olive leaf extract is used orally and appropriately. Olive leaf extract providing 51-100 mg oleuropein daily has been used with apparent safety for 6-8 weeks (92245,92247,101860). There is insufficient reliable information available about the safety of olive fruit extract when used in amounts greater than those found in foods.

PREGNANCY AND LACTATION:
Insufficient reliable information available; stick with amounts commonly found in foods.

(Read more about OLIVE)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Oregano leaf and oil have Generally Recognized as Safe (GRAS) status in the US (4912). There is insufficient reliable information available about the safety of oregano when used orally in amounts greater than those found in food. There is also insufficient reliable information available about the safety of oregano when used topically. Oregano oil in concentrations of greater than 1% may be irritating when applied to mucous membranes (67348,88188).

PREGNANCY: POSSIBLY UNSAFE
when used orally in medicinal amounts. Oregano is thought to have abortifacient and emmenagogue effects (19,7122,19104).

LACTATION:
There is insufficient reliable information available about the safety of oregano when used in medicinal amounts; avoid amounts greater than those found in food.

(Read more about OREGANO)

(Read more about OLIVE)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, oregano might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.  Details In vitro research shows that aristolochic acid isolated from oregano leaves has antithrombin activity (67164). It has also been reported that oregano oil inhibits arachidonic acid-induced, and ADP-induced, platelet aggregation (49445).

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, oregano might increase the risk for hypoglycemia when taken with antidiabetes drugs.  Details In vitro and animal research shows that oregano extracts might lower blood glucose levels (67191,67204,110122).

(Read more about OREGANO)

General ...Orally, olive fruit is well tolerated when used in typical food amounts. Olive leaf extract seems to be well tolerated.
Most Common Adverse Effects:
Orally: Headache and stomach discomfort.

Dermatologic ...Orally, one patient in one clinical trial reported bad skin and acne after using olive leaf extract (101860).

Gastrointestinal ...Orally, three patients in one clinical trial reported stomach ache after using olive leaf extract (101860).

Neurologic/CNS ...Orally, three patients in one clinical trial reported headache after using olive leaf extract (101860).

Psychiatric ...In one case report, a 67-year-old female experienced irritability, anger, a lack of control, and feelings of sadness and negativity after consuming a multi-ingredient product containing olive leaf extract 5 grams, horseradish root, and eyebright daily for 38 days. All psychiatric symptoms disappeared within days of stopping the combined product. It is hypothesized that the hydroxytyrosol component of olive leaf extract contributed to these symptoms due to its chemical similarity to dopamine; however, it is not clear if these symptoms were due to the olive leaf extract or to the other ingredients (96245).

Pulmonary/Respiratory ...Olive tree pollen can cause seasonal respiratory allergy (1543).

(Read more about OLIVE)

General ...Orally, oregano is well tolerated when used in amounts typically found in foods. There is currently a limited amount of information available about the safety of oregano when used in larger amounts as medicine.
Most Common Adverse Effects:
Orally: Gastrointestinal upset.
Topically: Dermatitis in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Systemic allergic reactions, including anaphylaxis, in sensitive individuals.

Dermatologic ...Oregano has been reported to cause allergic contact dermatitis (46902). Topically, oregano oil in concentrations of greater than 1% has been reported to cause irritation when applied to mucous membranes (67348,88188).

Gastrointestinal ...Orally, large amounts of oregano can cause gastrointestinal upset. Concentrated, non-emulsified oil of oregano can cause localized irritation of the gastrointestinal tract (6878).

Immunologic ...Systemic allergic reactions have been reported with oregano. A 45-year-old male developed pruritus, respiratory difficulty, hypotension, swelling of the lips and tongue, and facial edema after ingesting pizza seasoned with oregano. He had 2 similar episodes after ingesting foods seasoned with thyme, another member of the Lamiaceae family. He did not react to similar foods without the seasoning, and he had positive skin tests to plants of the Lamiaceae family (3705).

(Read more about OREGANO)