Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

SYN-30 30 mg Ingredients & Drug Interactions

by SNS Serious Nutrition Solutions

SYN-30 30 mg label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking SYN-30 30 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

SYN-30 30 mg is a dietary supplement by SNS Serious Nutrition Solutions with 1 active ingredient. Its ingredients are commonly taken for weight loss, athletic performance and energy, digestive upset.Based on those ingredients, 957 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Synephrine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against SYN-30 30 mg by SNS Serious Nutrition Solutions

Ask about any prescription or over-the-counter medication and we check it for interactions with SYN-30 30 mg by SNS Serious Nutrition Solutions — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of SYN-30 30 mg by SNS Serious Nutrition Solutions

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

SYN-30 contains one active ingredient: synephrine, a compound extracted from bitter orange. Synephrine is a stimulant that's used in weight-loss and athletic-performance supplements — it works on your nervous system to increase alertness and metabolism.

The capsule also contains several inactive ingredients (gelatin, rice flour, dicalcium phosphate, magnesium stearate, silicon dioxide, titanium dioxide, and FD&C Blue #1) that help form and color the capsule itself.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Bitter Orange's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: Fat burning, appetite control, and energy.
  • We looked for evidence on: Athletic performance, Fatigue, Obesity, Weight loss, Metabolic rate.
  • The closest evidence on file: Bitter Orange is rated "Insufficient Reliable Evidence To Rate" for Athletic performance (Natural Medicines).
  • Also on file: Bitter Orange is rated "Insufficient Reliable Evidence To Rate" for Fatigue, Obesity.

The evidence doesn't support using synephrine for hay fever, hair loss, sexual dysfunction, pre-procedure anxiety, or athletic performance — our data shows insufficient reliable evidence for all of these uses. If you're considering this product for one of those reasons, talk with your pharmacist or doctor about whether there's a better-supported option.

The evidence, ingredient by ingredient Bitter Orange

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Synephrine from bitter orange can affect your heart rate and blood pressure, so use it with caution — especially if you already have heart or blood pressure concerns. The most common side effects from oral use are high blood pressure and a rapid heartbeat, particularly when combined with caffeine or other stimulants.

Rare but serious side effects reported include heart attack, stroke, fainting, seizure, and dangerous heart rhythms. During pregnancy, the safety data advises against supplement amounts of bitter orange due to its stimulant effects and lack of safety information.

While breastfeeding, there isn't enough safety information available, so avoid supplement doses — talk with your doctor or pharmacist for personalized advice.

Side effects, ingredient by ingredient Bitter Orange

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Bitter Orange.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: diabetes medications; heart-rhythm medications.
  • For scale: 958 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking SYN-30, check whether you use MAOIs (older antidepressants), midazolam (Versed), QT interval-prolonging heart drugs, or any medications broken down by the liver enzyme CYP3A4 — these carry Major or Moderate interaction risks. Also check on diabetes medications, stimulant drugs, dextromethorphan (cough suppressants), and caffeine, all of which may interact.

The medication checker on this page will flag your exact medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

SYN-30 is a single-ingredient stimulant supplement with significant interactions — especially with blood pressure medications, heart drugs, MAOIs, and drugs broken down by your liver. If you take any prescription medication or have heart or blood pressure concerns, check your drugs against the medication tool on this page before starting.

Always run this by your pharmacist first.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jun 16, 2022.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about SYN-30 30 mg, straight from the product label.

Brand SNS Serious Nutrition Solutions
Net contents 180 Capsule(s)
Market status On market
Date entered into DSLD Jun 16, 2022
DSLD ID 266107
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for SYN-30 30 mg by SNS Serious Nutrition Solutions, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
180
IngredientAmount% DV
Synephrine30 mg--

Other ingredients: Gelatin, FD&C Blue #1, Titanium Dioxide, Rice Flour, Dicalcium Phosphate, Magnesium Stearate, Silicon Dioxide

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formulation

SYN-30 highlights/supports: Fat burning Appetite control Increased energy

Allergen Information: Not manufactured with yeast, wheat, gluten, soy, milk, egg, fish, shellfish, or tree nut ingredients.

Fat burning, appetite control, energy 30 mg. synephrine per capsule Syn-30 provides 30 mg. per capsule of synephrine. Synephrine is commonly used to help support fat burning, appetite control, and increased energy.

Formula

30 mg. Synephrine per capsule

General Statements

SNS SYN-30 can be stacked with Lean Edge, Thermagize XT, Focus XT, or a variety of other SNS products for improved synergistic results.

SNS Baseline Series Straight forward, cost effective sports nutrition.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Precautions

To report a serious adverse event, or obtain product information, contact Serious Nutrition Solutions, LLC. at 1-877-799-8778.

Allergen Information: Not manufactured with yeast, wheat, gluten, soy, milk, egg, fish, shellfish, or tree nut ingredients. Produced in a GMP facility that may process other ingredients containing these allergens.

Warnings: This product is for use by healthy adults over 18 years of age. Do not exceed recommended dosage. Consult a physician or qualified healthcare professional before using this or any dietary supplement, especially if you are at risk for, have been treated for, ore are diagnosed with high blood pressure, heart disease, thyroid disease, kidney disease, depression or other psychiatric conditions, renal disease, recurrent headaches, spasms, asthma, or are taking any prescription or OTC medications including but not limited to Monoamine Oxidase Inhibitors (MAOI).

Do not use if you are pregnant or nursing. Consult a physician or qualified healthcare professional before using this or any dietary supplement, especially if you are at risk for, have been treated for, ore are diagnosed with high blood pressure, heart disease, thyroid disease, kidney disease, depression or other psychiatric conditions, renal disease, recurrent headaches, spasms, asthma, or are taking any prescription or OTC medications including but not limited to Monoamine Oxidase Inhibitors (MAOI).

Keep stored in a cool, dry place away from children and animals.

Seals/Symbols

GMP Good Manufacturing Practice Product

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 1 capsule 1 to 3 times per day, preferably 30 minutes prior to meals.

Storage

Keep stored in a cool, dry place away from children and animals.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

SYN-30 30 mg by SNS Serious Nutrition Solutions label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

SYN-30 30 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in SYN-30 30 mg by SNS Serious Nutrition Solutions

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container180 Amounts shown are per serving.

Synephrine

Interacts with
957 drugs
30 mg per serving Form: Advantra Z

Bitter orange is a citrus fruit whose extracts contain synephrine, a mild stimulant often added to weight-loss and energy supplements. Evidence that i...

Synephrine monograph & interactions

Other (inactive) ingredients: Gelatin, FD&C Blue #1, Titanium Dioxide, Rice Flour, Dicalcium Phosphate, Magnesium Stearate, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

SYN-30 30 mg by SNS Serious Nutrition Solutions Drug Interactions

Want to check YOUR meds against SYN-30 30 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
957Drugs
10 Major 876 Moderate 71 Minor

Ingredients driving the most interactions

Synephrine 957

Individual Drug Interactions

The ingredients in SYN-30 30 mg interact with 957 drugs. Click any drug to see the details.

1 of the 1 ingredient in SYN-30 30 mg interact with drugs. Each result below shows which ingredient is responsible. Synephrine

Each ingredient & the kinds of drugs it affects

For each ingredient in SYN-30 30 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Synephrine13 drug types · 957 drugs

Midazolam (Versed)

Bitter orange might increase blood levels of midazolam.
One small clinical study shows that bitter orange juice can increase midazolam levels, likely through inhibition of cytochrome P450 3A4 (CYP3A4). Theoretically, bitter orange might increase the risk of midazolam-related adverse effects.

Likelihood Probable Evidence B
Monoamine Oxidase Inhibitors (Maois)

Theoretically, taking MAOIs with synephrine-containing bitter orange preparations might increase the hypertensive effects of synephrine, potentially leading to hypertensive crisis.
Bitter orange contains tyramine, octopamine, and synephrine, which are MAO substrates.

Likelihood Probable Evidence D
Antidiabetes Drugs

Theoretically, bitter orange might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Some clinical research shows that drinking a tea containing bitter orange and Indian snakeroot reduces fasting and postprandial glucose levels in patients with type 2 diabetes who are using antidiabetes drugs. However, it is unclear if these effects are due to bitter orange, Indian snakeroot, or the combination. An animal study also shows that p-synephrine in combination with gliclazide , a sulfonylurea, causes an additional 20% to 44% decrease in glucose levels when compared with gliclazide alone.

Likelihood Possible Evidence B
Caffeine

Bitter orange might increase blood pressure and heart rate when taken with caffeine.
Small clinical studies show that taking bitter orange in combination with caffeine can increase blood pressure and heart rate in otherwise healthy normotensive adults. Theoretically, this might increase the risk of serious cardiovascular adverse effects.

Likelihood Possible Evidence B
Colchicine

Bitter orange might affect colchicine levels.
Colchicine is a substrate of P-glycoprotein and cytochrome P450 3A4 (CYP3A4). Bitter orange has been reported to inhibit CYP3A4 and increase levels of CYP3A4 substrates. However, one small clinical study in healthy adults shows that drinking bitter orange juice 240 mL twice daily for 4 days and taking a single dose of colchicine 0.6 mg on the 4th day decreases colchicine peak serum levels by 24%, time to peak serum level by 1 hour, and overall exposure to colchicine by 20%. The clinical significance of this finding is unclear.

Likelihood Possible Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Bitter orange might increase levels of drugs metabolized by CYP3A4.
Small clinical studies suggest that single or multiple doses of freshly squeezed bitter orange juice 200-240 mL can inhibit CYP3A4 metabolism of drugs, causing increased drug levels and potentially increasing the risk of adverse effects. However, the extent of the effect of bitter orange on CYP3A4-mediated drug interactions is unknown. Some evidence suggests that bitter orange selectively inhibits intestinal CYP3A4, but not hepatic CYP3A4. Its effect on P-glycoprotein, which strongly overlaps with CYP3A4 interactions, is unclear. One small clinical study shows that drinking 8 ounces of freshly squeezed bitter orange juice has no effect on cyclosporine, which seems to be more dependent on hepatic CYP3A4 and P-glycoprotein than intestinal CYP3A4.

Likelihood Possible Evidence B
Dextromethorphan (Robitussin Dm, Others)

Bitter orange might increase blood levels of dextromethorphan.
One small clinical study shows that bitter orange juice increases dextromethorphan levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition. Theoretically, bitter orange might increase the risk for dextromethorphan-related adverse effects.

Likelihood Possible Evidence B
Felodipine (Plendil)

Bitter orange might increase blood levels of felodipine.
One small clinical study shows that bitter orange juice increases felodipine levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition. Theoretically, bitter orange might increase the risk for felodipine-related adverse effects.

Likelihood Probable Evidence B
Indinavir (Crixivan)

Bitter orange might increase blood levels of indinavir.
One small clinical study shows that bitter orange juice slightly increases indinavir levels, but this effect is likely to be clinically insignificant. Bitter orange selectively inhibits intestinal cytochrome P450 3A4 (CYP3A4); however, the metabolism of indinavir seems to be more dependent on hepatic CYP3A4. The effect of bitter orange on other protease inhibitors has not been studied.

Likelihood Possible Evidence B
Qt Interval-Prolonging Drugs

Theoretically, bitter orange might have an additive effect when combined with drugs that prolong the QT interval, potentially increasing the risk of ventricular arrhythmias.
One case report suggests that taking bitter orange in combination with other stimulants such as caffeine might prolong the QT interval in some patients.

Likelihood Possible Evidence D
Sildenafil (Viagra)

Bitter orange juice might increase blood levels of sildenafil.
A small clinical study in healthy adult males shows that drinking freshly squeezed bitter orange juice 250 mL daily for 3 days and taking a single dose of sildenafil 50 mg on the 3rd day increases the peak plasma concentration of sildenafil by 18% and the overall exposure to sildenafil by 44%. Theoretically, this may be due to inhibition of cytochrome P450 3A4 by bitter orange.

Likelihood Probable Evidence B
Stimulant Drugs

Theoretically, bitter orange might increase the risk of hypertension and adverse cardiovascular effects when taken with stimulant drugs.
Bitter orange appears to have stimulant effects.

Likelihood Possible Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, bitter orange might increase levels of drug metabolized by CYP2D6.
In vitro research shows that octopamine, a constituent of bitter orange, weakly inhibits CYP2D6 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Synephrine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for SYN-30 30 mg, from the product label.

SNS Serious Nutrition Solutions

See all SNS Serious Nutrition Solutions products
Name
Serious Nutrition Solutions, LLC
City
Danville
State
VA
ZipCode
24540
Phone Number
1-877-799-8778
Web Address
www.SeriousNutritionSolutions.com
Pharmacist Counseling Corner

SYN-30 30 mg by SNS Serious Nutrition Solutions: Common Questions

Does SYN-30 30 mg by SNS Serious Nutrition Solutions interact with any medications?
Yes. Based on its ingredients, SYN-30 30 mg has a known interaction with 957 medications, including 10 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
SYN-30 30 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant or breastfeeding?
During pregnancy, the safety data advises against supplement amounts of bitter orange due to stimulant effects and lack of safety information. While breastfeeding, there isn't enough safety data available — talk with your doctor or pharmacist about whether this product is right for you right now.
What does synephrine do?
Synephrine is a stimulant compound from bitter orange that increases alertness and metabolism. It works on your nervous system and can raise your heart rate and blood pressure.
What are the main side effects?
The most common side effects are high blood pressure and a rapid heartbeat, particularly when you combine it with caffeine or other stimulants. Rare but serious side effects include heart attack, stroke, fainting, seizure, and dangerous heart rhythms.
Does this product work for weight loss or athletic performance?
Our data shows insufficient reliable evidence to support synephrine for athletic performance. For weight loss, the data we hold doesn't cover that claim — talk with your pharmacist about what the research actually shows.
Can I take this with caffeine?
No — combining synephrine with caffeine can increase blood pressure and heart rate and raise the risk of serious cardiovascular side effects. Avoid taking this product if you're also drinking coffee, tea, energy drinks, or taking caffeine pills.
What are the inactive ingredients in this capsule?
The capsule contains gelatin, rice flour, dicalcium phosphate, magnesium stearate, silicon dioxide, titanium dioxide, and FD&C Blue #1 — these are fillers, binders, and coloring agents that don't add therapeutic effect.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if SYN-30 30 mg is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

SYN-30 30 mg label
Go deeper

The Full Monographs Behind SYN-30 30 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Bitter Orange

Interacts with 957 drugs

Bitter orange is a citrus fruit whose extracts contain synephrine, a mild stimulant often added to weight-loss and energy supplements. Evidence that it works for weight loss or performance i...

Read the full Bitter Orange monograph →
Sources

Sources & How We Checked

SYN-30 30 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 47 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Bitter Orange 47 references
  1. Penzak SR, Jann MW, Cold JA, et al. Seville (sour) orange juice: synephrine content and cardiovascular effects in normotensive adults. J Clin Pharmacol 2001;41:1059-63. PubMed
  2. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  3. Calapai G, Firenzuoli F, Saitta A, et al. Antiobesity and cardiovascular toxic effects of Citrus aurantium extracts in the rat: A preliminary report. Fitoterapia 1999;70:586-92. DOI
  4. Keogh AM, Baron DW. Sympathomimetic abuse and coronary artery spasm. Br Med J 1985;291:940.
  5. Malhotra S, Bailey DG, Paine MF, Watkins PB. Seville orange juice-felodipine interaction: comparison with dilute grapefruit juice and involvement of furocoumarins. Clin Pharmacol Ther 2001;69:14-23. PubMed
  6. Pellati F, Benvenuti S, Melegari M, Firenzuoli F. Determination of adrenergic agonists from extracts and herbal products of Citrus aurantium L. var. amara by LC. J Pharm Biomed Anal 2002;29:1113-9. . PubMed
  7. Colker CM, Kalman DS, Torina GC, et al. Effects of Citrus aurantium extract, caffeine, and St. John's wort on body fat loss, lipid levels, and mood states in overweight healthy adults. Curr Ther Res 1999;60:145-153. DOI
  8. Penzak SR, Acosta EP, Turner M, et al. Effect of Seville orange juice and grapefruit juice on indinavir pharmacokinetics. J Clin Pharmacol 2002;42:1165-70. PubMed
  9. Edwards DJ, Fitzsimmons ME, Schuetz EG, et al. 6',7'-Dihydroxybergamottin in grapefruit juice and Seville orange juice: effects on cyclosporine disposition, enterocyte CYP3A4, and P-glycoprotein. Clin Pharmacol Ther 1999;65:237-44. PubMed
  10. Di Marco MP, Edwards DJ, Wainer IW, Ducharme MP. The effect of grapefruit juice and seville orange juice on the pharmacokinetics of dextromethorphan: the role of gut CYP3A and P-glycoprotein. Life Sci 2002;71:1149-60. PubMed
  11. Visentin V, Morin N, Fontana E, et al. Dual action of octopamine on glucose transport into adipocytes: inhibition via beta3-adrenoceptor activation and stimulation via oxidation by amine oxidases. J Pharmacol Exp Ther 2001;299:96-104.
  12. Nykamp DL, Fackih MN, Compton AL. Possible association of acute lateral-wall myocardial infarction and bitter orange supplement. Ann Pharmacother 2004;38:812-6. PubMed
  13. Fugh-Berman A, Myers A. Citrus aurantium, an ingredient of dietary supplements marketed for weight loss: Current status of clinical and basic Research. Exp Biol Med 2004;229:698-704.
  14. Suzuki O, Matsumoto T, Oya M, Katsumata Y. Oxidation of synephrine by type A and type B monoamine oxidase. Experientia 1979;35:1283-4. PubMed
  15. Nasir JM, Durning SJ, Ferguson M, et al. Exercise-induced syncope associated with QT prolongation and ephedra-free Xenadrine. Mayo Clin Proc 2004;79:1059-62.. PubMed
  16. Firenzuoli F, Gori L, Galapai C. Adverse reaction to an adrenergic herbal extract (Citrus aurantium). Phytomedicine 2005;12:247-8. PubMed
  17. Bouchard NC, Howland MA, Greller HA, et al. Ischemic stroke associated with use of an ephedra-free dietary supplement containing synephrine. Mayo Clin Proc 2005;80:541-5. PubMed
  18. Haller CA, Benowitz NL, Jacob P 3rd. Hemodynamic effects of ephedra-free weight-loss supplements in humans. Am J Med 2005;118:998-1003.. PubMed
  19. Bui LT, Nguyen DT, Ambrose PJ. Blood pressure and heart rate effects following a single dose of bitter orange. Ann Pharmacother 2006;40:53-7. PubMed
  20. Min B, Cios D, Kluger J, White CM. Absence of QTc-interval-prolonging or hemodynamic effects of a single dose of bitter-orange extract in healthy subjects. Pharmacotherapy 2005;25:1719-24. PubMed
  21. Gange CA, Madias C, Felix-Getzik EM, et al. Variant angina associated with bitter orange in a dietary supplement. Mayo Clin Proc 2006;81:545-8. PubMed
  22. Jordan S, Murty M, Pilon K. Products containing bitter orange or synephrine: suspected cardiovascular adverse reactions. Canadian Adverse Reaction Newsletter 2004;14:3-4.
  23. Burke J, Seda G, Allen D, Knee TS. A case of severe exercise-induced rhabdomyolysis associated with a weight loss dietary supplement. Mil Med 2007;172:656-8. PubMed
  24. Gray, S. and Woolf, A. D. Citrus aurantium used for weight loss by an adolescent with anorexia nervosa. J Adolesc.Health 2005;37(5):414-415. PubMed
  25. Haller, C. A., Duan, M., Jacob, P., III, and Benowitz, N. Human pharmacology of a performance-enhancing dietary supplement under resting and exercise conditions. Br J Clin Pharmacol 2008;65(6):833-840. PubMed
  26. Thomas, J. E., Munir, J. A., McIntyre, P. Z., and Ferguson, M. A. STEMI in a 24-year-old man after use of a synephrine-containing dietary supplement: a case report and review of the literature. Tex.Heart Inst.J 2009;36(6):586-590.
  27. Campbell-Tofte, J. I., Molgaard, P., Josefsen, K., Abdallah, Z., Hansen, S. H., Cornett, C., Mu, H., Richter, E. A., Petersen, H. W., Norregaard, J. C., and Winther, K. Randomized and double-blinded pilot clinical study of the safety and anti-diabetic ef
  28. Seifert, J. G., Nelson, A., Devonish, J., Burke, E. R., and Stohs, S. J. Effect of acute administration of an herbal preparation on blood pressure and heart rate in humans. Int J Med Sci 2011;8(3):192-197. PubMed
  29. Stohs, S. J., Preuss, H. G., Keith, S. C., Keith, P. L., Miller, H., and Kaats, G. R. Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. Int J Med
  30. Wason, S., DiGiacinto, J. L., and Davis, M. W. Effects of grapefruit and Seville orange juices on the pharmacokinetic properties of colchicine in healthy subjects. Clin Ther 2012;34(10):2161-2173. PubMed
  31. Kaats, G. R., Miller, H., Preuss, H. G., and Stohs, S. J. A 60day double-blind, placebo-controlled safety study involving Citrus aurantium (bitter orange) extract. Food Chem Toxicol. 2013;55:358-362.
  32. Calapai, G., Firenzuoli, F., Saitta, A., Squadrito, F. R., Arlotta, M., Costantino, G., and Inferrera, G. Antiobesity and cardiovascular toxic effects of Citrus aurantium extracts in the rat: a preliminary report. Fitoterapia 12-1-1999;70(6):586-592. DOI
  33. Colker, C., Kalman, D., and Torina, G. Effects of Citrus aurantium extract, caffeine, and St. John's Wort on body fat loss, lipid levels, and mood states in overweight healthy adults. Curr Ther Res 1999;60:145-153. DOI
  34. Shara M, Stohs SJ. Safety evaluation of Bitter orange extract (p-synephrine) in healthy volunteers. J.Amer.Coll.Nutr. 2011;30:358.
  35. Lynch B. Review of the safety of p-synephrine and caffeine. Intertek-Cantox Report, 2013;1-20.
  36. Smith TB, Staub BA, Natarajan GM, et al. Acute myocardial infarction associated with dietary supplements containing 1,3-dimethylamylamine and Citrus aurantium. Tex Heart Inst J 2014;41(1):70-2. PubMed
  37. Shara M, Stohs SJ, Mukattash TL. Cardiovascular safety of oral p-synephrine (bitter orange) in healthy subjects: a randomized placebo-controlled cross-over clinical trial. Phytother Res. 2016;30(5):842-7.
  38. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed
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See these in context on the Bitter Orange monograph →

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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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