Buy Phoslax Online (Phospho-Soda Laxative Grape)
What is Phoslax?
What is Phoslax?
Phoslax laxative is used to relieve constipation and to prepare the bowel before certain medical procedures, such as a colonoscopy. It works by helping the body produce a bowel movement. This brand-name product is sometimes compared to older products like Phospho-Soda. It is important to follow the recommended dosage carefully to avoid side effects.
Phoslax is regulated for safety and quality, and products may meet USP standards. It is commonly used by adults and sometimes by children over 2 years of age, depending on the healthcare provider’s advice.
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Phoslax
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Phospho-Soda Laxative Grape (generic Phoslax)
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Important information about Phoslax
The active ingredient in Phoslax is sodium phosphate, including dibasic sodium phosphate and monobasic sodium phosphate. This laxative works by drawing water into the intestines. This increases fluid in the bowel, which softens stool and triggers a bowel movement. The increased fluid also helps empty the colon quickly, which is why it is used before procedures like a colonoscopy.
Electrolytes such as sodium, calcium, and magnesium may be affected during use, so careful dosing is important. Inactive ingredients may include glycerin, saccharin, and sodium benzoate to improve taste and stability.
Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Phoslax. However, the following is a synopsis of the general guidelines for the use of Phoslax:
- Take Phoslax exactly as directed using the recommended dosage. It is usually taken as an oral solution.
- Drink plenty of clear liquids before, during, and after use to prevent dehydration and support bowel cleansing.
- For colonoscopy preparation, your healthcare provider may give you a specific schedule to follow.
- Do not exceed the recommended amount, as taking too much sodium phosphate can be harmful.
- Phoslax is typically used short-term and should not be taken regularly for ongoing constipation without medical advice.
Some mild or common side effects of Phoslax include:
- Abdominal pain or cramping
- Nausea
- Bloating
- Frequent bowel movements
Some individuals may experience serious side effects while using Phoslax. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:
- Severe abdominal pain
- Chest pain
- Signs of dehydration, such as dizziness or weakness
- Irregular heartbeat due to electrolyte imbalance
- Symptoms of colitis or worsening digestive issues
These are not all of the possible side effects of Phoslax. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.
Before starting Phoslax, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including if you have:
- Kidney disease
- Heart conditions
- Electrolyte imbalances involving calcium or magnesium
- A history of colitis
- Bowel obstruction
- Use of medications such as diuretics
You should follow all instructions carefully and avoid using more than directed. Health Canada has issued guidance about the proper use of phosphate-based laxatives to reduce risks.
Phoslax should not be used in individuals who:
- Have bowel obstruction
- Have severe kidney disease
- Have known hypersensitivity to sodium phosphate products
- Are unable to maintain proper fluid intake
Phoslax is a fast-acting laxative. It usually produces a bowel movement within 30 minutes to 6 hours after taking a dose. For colonoscopy preparation, timing will depend on the schedule provided by your healthcare provider.
When Phoslax is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:
- Diuretics
- Blood pressure medications
- Other laxative products
- Supplements containing calcium or magnesium
These combinations may increase the risk of dehydration or electrolyte imbalance.
Phoslax is available as an oral solution with dosing based on volume and electrolyte content, often measured in mmol. The product may be available in different strengths or SKU formats. The recommended dosage depends on age, reason for use, and overall health. Always follow instructions provided by your healthcare provider.
Store Phoslax at room temperature and keep it tightly closed. Keep the medication out of the reach of children and avoid exposure to excessive heat or moisture.
Phoslax is manufactured by Odan Laboratories Ltd., a company that produces a range of pharmaceutical products.
Yes, other sodium phosphate laxative products are available as generics. These may contain similar active ingredients but may differ in formulation and taste.
Phoslax is typically used short term, so it can be stopped once the desired bowel movement or bowel cleansing is achieved. Do not continue using it regularly without consulting your healthcare provider.
Sodium phosphate laxatives are used with caution during pregnancy, and your healthcare provider will decide if it is appropriate for you. Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you.
Phoslax should be used during breastfeeding only if recommended by a healthcare provider, as caution is advised due to potential fluid and electrolyte changes. Talk to your doctor if you are already breastfeeding or if you have any plans to breastfeed. They will know or recommend what is best for you.
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Click to joinImportant information about buying Phoslax from UniversalDrugstore™
We ship to destinations within the United States, including Alaska and Hawaii, as well as internationally. Delivery typically takes about 2 weeks for orders shipped within the U.S. and Canada, and about 4 weeks for international orders, depending on your location and customs processing.
Once you complete your order, we process, verify, and dispatch your medication. You’ll receive email updates at each stage, including tracking details once your order ships. If any additional documentation is needed (such as a valid prescription), we’ll contact you promptly. Once approved, your order is charged and delivered directly to your doorstep.
Orders are typically processed within 1–3 business days once all required documents are received and approved. Standard delivery times range from 10–18 business days, depending on your location.
Yes! Once your medication ships, you will receive an email with tracking information so you can monitor your shipment every step of the way.
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Universal Drugstore does not bill private health insurance directly, but we provide a detailed invoice that you can submit to your insurer for possible reimbursement. Many insurers will accept Universal Drugstore’s documents, but if you have any questions, check with your insurance company prior to purchasing.
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Universal Drugstore offers many generic alternatives that provide the same active ingredients at a lower cost. Search for your medication and compare pricing for generic vs. brand-name options. Generic availability depends on the medication.
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Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Jamie Winn, PharmD, is a licensed pharmacist and seasoned medical content reviewer with over 20 years of experience in clinical pharmacy, patient care, and healthcare leadership.
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Shirley is a Medical Writer and first-year Doctor of Pharmacy (PharmD) student at the University of Alberta, where she is building on her strong foundation in health sciences and patient care.
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