What Is Kristalose? Uses, Dosage, and What You Need to Know in 2026

Kristalose is the brand name for lactulose powder for oral solution, a prescription medication used to treat chronic constipation in adults. It is manufactured by Cumberland Pharmaceuticals Inc. in Nashville, Tennessee and is available in single-dose powder packets that you dissolve in water before drinking.

Here is everything you need to know about Kristalose in 2026 — what it does, how to take it, what to expect, and how it compares to alternatives.

What Is Kristalose Used For?

Kristalose is FDA-approved for the treatment of constipation in adults. Specifically, clinical studies show that lactulose therapy increases both the number of bowel movements per day and the number of days on which bowel movements occur in patients with a history of chronic constipation.

The active ingredient — lactulose — also has a second FDA-approved use in liquid form (not Kristalose powder): the prevention and treatment of hepatic encephalopathy, a serious complication of liver disease. If you have liver disease, your doctor may prescribe generic lactulose solution rather than Kristalose powder.

How Does Kristalose Work?

Kristalose is an osmotic laxative. It works by drawing water into the colon, which softens the stool and makes it easier to pass. Unlike stimulant laxatives (like senna or bisacodyl), Kristalose does not force contractions — it simply creates the right conditions in your colon for a more natural bowel movement.

Lactulose is poorly absorbed from the gastrointestinal tract. Oral doses travel to the colon virtually unchanged, where bacteria break it down into organic acids (mainly lactic acid). This acidifies and increases the osmotic pressure in the colon, drawing water in and softening stool. Because the drug needs to reach the colon first, it takes 24–48 hours to produce a bowel movement — so patience is required, especially when first starting therapy.

What Does Kristalose Come In? (Forms and Strengths)

Kristalose is available in single-dose powder packets in two strengths:

10 gram packets — typically for initial or lower dosing

20 gram packets — for patients who need a higher dose

Each packet contains the crystallized lactulose powder. The powder is odorless and dissolves into a colorless to slightly pale yellow solution.

How Do You Take Kristalose?

Open one packet (or as directed by your doctor — 1 to 2 packets daily)

Dissolve the entire contents in half a glass (4 ounces / 120 mL) of water

Stir until fully dissolved — the solution will be colorless or faintly yellow

Drink the full solution

Expect a bowel movement within 24–48 hours — not immediately

Store packets at room temperature (59–86°F / 15–30°C). Do not refrigerate or freeze. Keep away from children.

What Is the Typical Kristalose Dosage?

Starting dose: 10–20g (1–2 packets) once daily

Maximum dose: Up to 40g daily if lower doses are insufficient

Goal: Producing regular, comfortable bowel movements — typically 1–3 per day

Always follow your doctor's specific dosing instructions, as your optimal dose depends on your individual response.

Is Kristalose a Controlled Substance?

No. Kristalose (lactulose) is not a controlled substance. It has no potential for abuse or dependence, requires no special DEA prescribing authorization, and can be prescribed by any licensed healthcare provider including nurse practitioners and physician assistants. It can also be prescribed via telehealth.

How Does Kristalose Differ From Generic Lactulose?

Kristalose and generic lactulose contain the same active ingredient at the same dose strength. The key difference is the formulation:

Kristalose: Crystallized powder in pre-measured single-dose packets; you dissolve in water before drinking

Generic lactulose: Pre-mixed liquid syrup (10g/15 mL); you measure a liquid dose with a cup or spoon

Generic lactulose costs significantly less — $8–$15 with a GoodRx coupon vs. $100–$385 for Kristalose depending on discounts. If cost is a concern or availability is an issue, talk to your doctor about whether the generic liquid is appropriate for you. And if you're specifically looking to fill your Kristalose prescription, medfinder can help you find a pharmacy that has it in stock.