Mastica Chios


Helps relieve heartburn

  • A health-promoting gum resin derived from the Pistacia lentiscus tree
  • Helps heal and soothe peptic and gastric ulcers
  • Inhibits Helicobacter pylori 
  • Relieves gastric and intestinal inflammation
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Mastic gum is the gummy resin of the mastic tree – Pistacia lentiscus, a relative of the pistachio tree. The mastic tree is found almost exclusively on the Greek island of Chios, the birthplace of Hippocrates, the traditional father of medicine. Mastic gum has historically been used in medicine to fight gastric and intestinal inflammation.

In modern society, mastic gum has proven useful for fighting gastritis and heartburn as well as overall gastric and intestinal inflammation. Studies have found that supplementing with mastic gum not only relieves the symptoms of these painful conditions but can actually help heal the stomach, possibly by killing H. pylori bacteria. Mastic gum is an excellent natural alternative for those who have experienced the negative long-term side effects of antacids, proton pump inhibitors, antibiotics and other medications that treat the symptoms of heartburn but not the cause.

AOR Advantage

AOR’s Mastica Chios is derived exclusively from mastic gum from the pistachio trees found on the Greek island of Chios.




Mastica Chios is mastic gum, the resinous extract of the mastic tree (Pistacia lentiscus) grown on the Greek island of Chios. It is traditionally used in Ayurveda for Adhmana (excessive gas formation in the stomach and intestines). Research shows that it helps alleviate stomach pain and heartburn associated with functional dyspepsia.


AOR™ guarantees that no ingredients not listed on the label have been added to the product. Contains no wheat, gluten, corn, nuts, peanuts, sesame seeds, sulphites, mustard, soy, dairy, eggs, fish, shellfish or any animal by product.

Adult Dosage

Take one capsule three times daily on an empty stomach, or as directed by a qualified health care practitioner.


For occasional use only. Consult a health care practitioner for use beyond two weeks, if symptoms persist or worsen, if you have diabetes mellitus or Crohn’s disease or are taking hypoglycemic or hypolipidemic agents. Do not use if pregnant or breastfeeding or if you have an allergy to Anacardiaceae family plants (eg. pistachios). Discontinue use if hypersensitivity (eg. allergy) occurs.

Main Applications
  • Ulcers (peptic and gastric)
  • Heartburn

The information and product descriptions appearing on this website are for information purposes only, and are not intended to provide or replace medical advice to individuals from a qualified health care professional. Consult with your physician if you have any health concerns, and before initiating any new diet, exercise, supplement, or other lifestyle changes.

Serving Size: One Capsule

Non-medicinal Ingredients: microcrystalline cellulose, sodium stearyl fumarate. Capsule: hypromellose.

Anti-inflammatory/Antioxidant Activity

Study #1:

This 2011 study evaluated the potential role of the antioxidant activity of Chios mastic gum. Gum of Chios mastic (Pistacia lentiscus var. chia) is a natural antimicrobial agent that has found extensive use in pharmaceutical products and as a nutritional supplement. The molecular mechanisms of its anti-inflammatory activity, however, are not clear.

Scavenging of superoxide radical was investigated by electron spin resonance and spin trapping technique using EMPO spin trap in xanthine oxidase system. Superoxide production in endothelial and smooth muscle cells stimulated with TNF-α or angiotensin II and treated with vehicle (DMSO) or mastic gum (0.1-10 μg/ml) was measured by DHE and HPLC. Cellular H2O2 was measured by Amplex Red. Inhibition of protein kinase C (PKC) with mastic gum was determined by the decrease of purified PKC activity, by inhibition of PKC activity in cellular homogenate and by attenuation of superoxide production in cells treated with PKC activator phorbol 12-myristate 13-acetate (PMA).

Spin trapping study did not show significant scavenging of superoxide by mastic gum itself. However, mastic gum inhibited cellular production of superoxide and H2O2 in dose dependent manner in TNF-α treated rat aortic smooth muscle cells but did not affect unstimulated cells. TNF-α significantly increased the cellular superoxide production by NADPH oxidase, while mastic gum completely abolished this stimulation. Mastic gum inhibited the activity of purified PKC, decreased PKC activity in cell homogenate, and attenuated superoxide production in cells stimulated with PKC activator PMA and PKC-dependent angiotensin II in endothelial cells.

The researchers suggest that mastic gum inhibits PKC which attenuates production of superoxide and H2O2 by NADPH oxidases. This antioxidant property may have direct implication to the anti-inflammatory activity of the Chios mastic gum.

Triantafyllou A, Bikineyeva A, Dikalova A, Nazarewicz R, Lerakis S, Dikalov S. Anti-inflammatory activity of Chios mastic gum is associated with inhibition of TNF-alpha induced oxidative stress. Nutr J. 2011;10:64. Published 2011 Jun 6. doi:10.1186/1475-2891-10-64

Study #2:

This 2019 review summarises the research evidence from preclinical and clinical studies regarding the antioxidant and anti-inflammatory potential of Chios mastic (Pistacia lentiscus var. chia). ‘Mastiha’ is a natural product of the Mediterranean basin with several health benefits as investigated the last decades. MEDLINE, COHRANE and search terms “Mastiha”, “Mastic gum”, “Chios mastic” and “Pistacia lentiscus” were used. The search was limited by selecting only articles written in English literature, published between 2003 and 2019 that were experimental studies on Mastiha resinous exudate (review articles and individual case reports were excluded). Additional searches were performed using “oxidative stress” and “inflammation”. A total of 19 studies met our criteria and were included in this review. Currently, there are more preclinical than clinical data available. Taken all together, the antioxidant potential of Mastiha is most probably owed to the inhibition of protein kinase, while its anti-inflammatory capacity may be the result of the inhibition of NF-κB activation. Further clinical studies in large populations are necessary.

Papada E, Kaliora AC. Antioxidant and Anti-Inflammatory Properties of Mastiha: A Review of Preclinical and Clinical Studies. Antioxidants (Basel). 2019;8(7):208. Published 2019 Jul 5. doi:10.3390/antiox8070208

Study #3:

This 2009 study examined Chios mastic gum extract and isolated phytosterol tirucallol anti-inflammatory activity in human aortic endothelial cells. Chios mastic gum (CMG) is a white, semitransparent, natural resin that is obtained as a trunk exudate from mastic trees. Triterpenic compounds and phytosterols like tirucallol are among its major components. CMG has been associated with cardiovascular protection, exerting its effect mainly through increasing the antioxidant defense system, and effectively lowering the levels of serum cholesterol in human subjects. However, data on its anti-inflammatory effect on endothelium are scarce. Attachment of leukocytes to the vascular endothelium and the subsequent migration of cells into the vessel wall are early events in atherogenesis, and this process requires the expression of endothelial adhesion molecules. In this study, we examined the effect of CMG neutral extract (25-200 microg/ml) and tirucallol (0.1-100 microM) on the following: 1) the expression of adhesion molecules (VCAM-1 and ICAM-1) by Cell ELISA and 2) the attachment of monocytes (U937 cells) in TNF-alpha stimulated Human Aortic Endothelial Cells (HAEC) by Adhesion assay. The impact of treatment with CMG neutral extract and tirucallol in NFkB phosphorylation was also examined by a cell-based ELISA kit.

The researchers concluded that both CMG extract and tirucallol inhibit significantly VCAM-1 and ICAM-1 expression in TNF-alpha-stimulated HAEC. They also significantly inhibit the binding of U937 cells to TNF-alpha-stimulated HAEC and attenuate the phosphorylation of NFkB p65. This study extends existing data regarding the cardioprotective effect of CMG, expands the spectrum of known phytosterols with potent antiatheromatic activity, provides new insight into the mechanisms underlying the beneficial effect of CMG on endothelial function, and may aid in design of new therapy for intervention in atherosclerosis.

Loizou S, Paraschos S, Mitakou S, Chrousos GP, Lekakis I, Moutsatsou P. Chios mastic gum extract and isolated phytosterol tirucallol exhibit anti-inflammatory activity in human aortic endothelial cells. Exp Biol Med (Maywood). 2009;234(5):553-561. doi:10.3181/0811-RM-338

Treatment of Functional Dyspepsia

Study #1:

A 2010, prospective randomised double-blind placebo-controlled trial assessed the efficacy of Chios mastic gum in patients with functional dyspepsia. 148 patients fulfilling Rome II criteria for functional dyspepsia were randomly assigned to receive either Chios mastic gum 350 mg three times daily or placebo. After three weeks of treatment the change from baseline in the severity of symptoms of functional dyspepsia was assessed using the Hong Kong index of dyspepsia. Patients’ global assessment of efficacy was also evaluated.

The symptom score after treatment was significantly lower in the Chios mastic gum than in the placebo group ((14.78+/-1.78) vs (19.96+/-1.83)) (p<0.05). There was a marked improvement of symptoms in 40% of patients receiving placebo and in 77% of patients receiving Chios mastic gum (p<0.02). Individual symptoms that showed significant improvement with Chios mastic gum were: stomach pain in general, stomach pain when anxious, dull ache in the upper abdomen and heartburn (<0.05 for all four symptoms). The researchers concluded that Chios mastic gum significantly improves symptoms in patients with functional dyspepsia compared to placebo.

Dabos KJ, Sfika E, Vlatta LJ, Frantzi D, Amygdalos GI, Giannikopoulos G. Is Chios mastic gum effective in the treatment of functional dyspepsia? A prospective randomised double-blind placebo-controlled trial. J Ethnopharmacol. 2010;127(2):205-209. doi:10.1016/j.jep.2009.11.021

Helicobacter pylori Eradication

Study #1:

In this 2009, randomized, pilot study, the researchers studied the effect of pure mastic gum on Helicobacter pylori (H. pylori) eradication in patients suffering from an H. pylori infection. 52 patients were randomized to receive either 350 mg three times a day (tid) of pure mastic gum for 14 days (Group A), or 1,05 g tid of pure mastic gum (Group B) for 14 days, or pantoprazole 20 mg twice a day (bd) plus pure mastic gum 350 mg tid for 14 days (Group C) or pantoprazole 20 mg bd plus amoxicillin 1g bd plus clarithromycin 500 mg bd for 10 days (Group D). All patients harboured H. pylori before entering the study and that was confirmed by a (13)C urea breath test (UBT). H. pylori eradication was tested by a UBT 5 weeks after completion of the eradication regime. Eradication of H. pylori was confirmed in 4/13 patients in Group A and in 5/13 in Grour B. No patient in Group C achieved eradication whereas 10/13 patients in Group D had a negative UBT. There were no statistically significant differences in mean UBT values in Groups A, B, C although there was a trend in Group A (p=0.08) and in Group B (p=0.064). The difference was significant in Group D (p=0.01). All patients tolerated mastic gum well and no serious adverse events were reported. Mastic gum has bactericidal activity on H. pylori in vivo.

Dabos KJ, Sfika E, Vlatta LJ, Giannikopoulos G. The effect of mastic gum on Helicobacter pylori: a randomized pilot study. Phytomedicine. 2010;17(3-4):296-299. doi:10.1016/j.phymed.2009.09.010

Study #2:

In this 2007 study, the extract and pure major constituents of Chios mastic gum (resin of Pistacia lentiscus var. chia) were tested for their activities against Helicobacter pylori in vivo in mice and in vitro. A total mastic extract without polymer (TMEWP) was prepared after removal of the contained insoluble polymer in order to ameliorate solubility and enhance in vivo activity. Administration of TMEWP to H. pylori SS1-infected mice over the period of three months with an average dose of 0.75 mg/day led to an approximately 30-fold reduction in the H. pylori colonization (1.5 log CFU/g of tissue). However, no attenuation in the H. pylori-associated chronic inflammatory infiltration and the activity of chronic gastritis was observed. To further characterize potential active mastic constituents, the TMEWP was separated into an acidic and a neutral fraction. Both were extensively characterized by nuclear magnetic resonance and mass spectroscopy to elucidate the structure of the components contained within each fraction. After chromatographic separation, the acid fraction gave the major triterpenic acids, while the neutral fraction gave several triterpenic alcohols and aldehydes. Mastic extracts and isolated pure triterpenic acids were tested for in vitro activity against a panel of 11 H. pylori clinical strains. The acid fraction was found to be the most active extract (minimum bactericidal concentration [MBC], 0.139 mg/ml), and the most active pure compound was isomasticadienolic acid (MBC, 0.202 mg/ml [0.443 mM]). Our results show that administration of TMEWP may be effective in reducing H. pylori colonization and that the major triterpenic acids in the acid extract may be responsible for such an activity.

Paraschos S, Magiatis P, Mitakou S, et al. In vitro and in vivo activities of Chios mastic gum extracts and constituents against Helicobacter pylori. Antimicrob Agents Chemother. 2007;51(2):551-559. doi:10.1128/AAC.00642-06

Study #3:

In this study 2001 study, the researchers evaluated the antibacterial activity of mastic gum, a resin obtained from the Pistacia lentiscus tree, against clinical isolates of Helicobacter pylori. The minimal bactericidal concentrations (MBCs) were obtained by a microdilution assay. Mastic gum killed 50% of the strains tested at a concentration of 125 microg/ml and 90% at a concentration of 500 microg/ml. The influence of sub-MBCs of mastic gum on the morphologies of H. pylori was evaluated by transmission electron microscopy. The lentiscus resin induced blebbing, morphological abnormalities and cellular fragmentation in H. pylori cells.

Marone P, Bono L, Leone E, Bona S, Carretto E, Perversi L. Bactericidal activity of Pistacia lentiscus mastic gum against Helicobacter pylori. J Chemother. 2001;13(6):611-614. doi:10.1179/joc.2001.13.6.611

Treatment of Gastric/Duodenal Ulcers

Study #1:

A 1984, double-blind clinical trial investigated the treatment of duodenal ulcer with mastic and placebo in thirty-eight patients with symptomatic and endoscopically proven duodenal ulcer. The trial aimed to compare the therapeutic responses to mastic (1 g daily, twenty patients) and placebo (lactose, 1 g daily, eighteen patients) given orally over a period of two weeks. Symptomatic relief was obtained in 16 (80%) patients on mastic and in nine (50%) patients on placebo, while endoscopically proven healing occurred in fourteen (70%) patients on mastic and four (22%) patients on placebo. The differences between treatments were highly significant (P less than 0.01). Mastic was well tolerated and did not produce side effects. The researchers concluded that mastic has an ulcer healing effect, but further studies are needed to establish its role in treating peptic ulcer.

Al-Habbal MJ, Al-Habbal Z, Huwez FU. A double-blind controlled clinical trial of mastic and placebo in the treatment of duodenal ulcer. Clin Exp Pharmacol Physiol. 1984;11(5):541-544. doi:10.1111/j.1440-1681.1984.tb00864.x

Study #2:

In this 1986 study, the effect of mastic, a concrete resinous exudate obtained from the stem of the tree Pistacia lentiscus, has been studied on experimentally-induced gastric and duodenal ulcers in rats. Mastic at an oral dose of 500 mg/kg produced a significant reduction in the intensity of gastric mucosal damage induced by pyloric ligation, aspirin, phenylbutazone, reserpine and restraint + cold stress. It produced a significant decrease of free acidity in 6-h pylorus-ligated rats and a marked cytoprotective effect against 50% ethanol in rats which could be reversed by prior treatment with indomethacin. The protective effect was not seen when it was given intraperitoneally in phenylbutazone and restraint + cold stress models. The reduction in the intensity of ulceration in cysteamine-induced duodenal ulcers was not found to be statistically significant in mastic-pretreated rats. The results suggest that mild antisecretory and a localized adaptive cytoprotectant action may be responsible for its anti-ulcer activity. These observations support the results of an earlier study on the clinical effectiveness of mastic in the therapy of duodenal ulcer.

Al-Said MS, Ageel AM, Parmar NS, Tariq M. Evaluation of mastic, a crude drug obtained from Pistacia lentiscus for gastric and duodenal anti-ulcer activity. J Ethnopharmacol. 1986;15(3):271-278. doi:10.1016/0378-8741(86)90165-0