Velphoro Side Effects: What to Expect and When to Call Your Doctor

When you start Velphoro (sucroferric oxyhydroxide), your doctor has told you it will help control your phosphorus levels — but nobody wants to be surprised by unexpected side effects. Here's a straightforward guide to what Velphoro can cause, what's normal, and what symptoms should prompt a call to your healthcare provider.

Common Side Effects (Usually Mild and Temporary)

In clinical trials involving over 1,000 dialysis patients, the most frequently reported side effects of Velphoro were:

• Discolored (dark or black) stools — 12% of patients. This is the most common side effect and is considered normal with iron-containing medications. The iron in Velphoro reacts in your gut to create a dark stool color. This does not mean you are bleeding internally. However, because black stools can sometimes indicate gastrointestinal bleeding, let your doctor know about any black stools when they first appear so they can rule out other causes.

• Diarrhea — 6% of patients. Loose stools or diarrhea may occur, especially when you first start the medication. This often improves after the first few weeks as your body adjusts.

• Tooth staining. Velphoro can stain your teeth over time due to its iron content. Maintaining good dental hygiene — brushing teeth after taking Velphoro — can minimize this effect. Talk to your dentist if staining is a concern.

• Nausea. Some patients experience mild nausea, particularly when taking higher doses. Chewing the tablet thoroughly and taking it with a full meal (not just a snack) can help reduce nausea.

• Constipation. Some patients report increased constipation, especially at higher doses. Stay within your fluid allowance (as advised by your dialysis team) and let your nephrologist know if constipation is severe.

How to Minimize Common Side Effects

• Always take Velphoro with a full meal — not between meals. It only works when there is food (phosphorus) to bind in your gut.

• Chew the tablet completely — do not swallow whole. Crushing the tablet in a pill crusher also works well.

• Give it a few weeks — GI side effects tend to improve as your body adjusts.

• Brush your teeth after taking Velphoro to minimize tooth staining.

Serious Side Effects — When to Call Your Doctor

While serious side effects from Velphoro are uncommon, you should contact your doctor or seek emergency care immediately if you experience any of the following:

• Signs of a severe allergic reaction: Hives, rash, swelling of the face, lips, tongue, or throat; difficulty breathing; severe itching. Stop Velphoro and call 911 or go to the nearest emergency room.

• Signs of gastrointestinal bleeding: Black, tarry, or blood-streaked stools that concern you; vomiting blood or material that looks like coffee grounds; severe abdominal pain. Note: dark stools from Velphoro's iron are expected — but actual blood in the stool has a different appearance and consistency.

• Iron overload concerns: If you have hemochromatosis or other iron-storage disorders, Velphoro may not be appropriate for you. Tell your doctor if you have a history of iron accumulation. Your nephrologist will monitor your serum iron, ferritin, and TSAT levels during Velphoro therapy.

Special Situations and Cautions

• Peritonitis or recent GI surgery: Patients with active peritonitis during peritoneal dialysis, significant GI disorders, or those who have had recent major GI surgery were not included in Velphoro clinical trials. Your doctor will monitor you more closely if any of these apply.

• Hereditary fructose intolerance: Velphoro contains sucrose and starches that break down into glucose, fructose, and maltose. If you have hereditary fructose intolerance or glucose-galactose malabsorption, do not take Velphoro.

Also important: Velphoro can interfere with other medications you take. See our complete guide to Velphoro drug interactions for the full list.