Comprehensive medication guide to Kristalose including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$50 copay depending on plan; many commercial insurance plans cover generic lactulose at Tier 1–2 with minimal copay. Brand Kristalose may require prior authorization or step therapy; Medicare Part D typically covers generic lactulose but may not cover brand Kristalose.
Estimated Cash Pricing
$307–$385 retail for brand Kristalose; as low as $5/month with the Cumberland Pharmaceuticals manufacturer coupon, or approximately $108 with a GoodRx coupon for a 30-day supply. Generic lactulose liquid is $8–$15 with GoodRx or SingleCare for a comparable supply.
Medfinder Findability Score
55/100
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Kristalose is the brand name for lactulose powder for oral solution, a prescription osmotic laxative manufactured by Cumberland Pharmaceuticals Inc. in Nashville, Tennessee. It is FDA-approved for the treatment of chronic constipation in adults.
Unlike generic lactulose, which is available as a pre-mixed liquid syrup, Kristalose comes as crystallized powder in single-dose packets — either 10g or 20g per packet — that you dissolve in water before drinking. This format offers convenience and precise dosing, making it especially useful for elderly patients or those with motor limitations who may struggle to measure liquid accurately.
Kristalose is not a controlled substance and has no abuse potential. It can be prescribed by any licensed healthcare provider including primary care physicians, gastroenterologists, nurse practitioners, and physician assistants. It is also available via telehealth prescription.
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Kristalose is classified as an osmotic laxative and colonic acidifier. The active ingredient, lactulose, is a synthetic disaccharide (made from galactose and fructose) that is not absorbed by the human small intestine. It travels to the colon virtually unchanged, where colonic bacteria break it down into organic acids — primarily lactic acid — along with small amounts of formic and acetic acids.
These organic acids increase osmotic pressure inside the colon, which draws water from surrounding tissues into the bowel. This softens the stool and promotes bowel movements. The process also slightly acidifies the colon contents, which has a secondary benefit of converting ammonia (NH3) into ammonium ion (NH4+) — which cannot be reabsorbed into the bloodstream. This is why lactulose (in liquid form) is also used to treat hepatic encephalopathy.
Because lactulose must travel to the colon before its mechanism activates, Kristalose typically takes 24–48 hours to produce a bowel movement. Less than 3% of an oral dose is absorbed into the bloodstream; the rest is expelled with stool.
10 g — powder packet for oral solution
Single-dose packet dissolved in 4 oz water; usual starting dose
20 g — powder packet for oral solution
Single-dose packet for patients requiring higher dosing; can be used daily
Kristalose is not on the FDA's official drug shortage list as of 2026. However, patients frequently encounter local availability gaps because Kristalose is a brand-name product manufactured by a single company (Cumberland Pharmaceuticals). Pharmacies stock medications based on demand, and since most lactulose prescriptions are filled with cheaper generic liquid, many pharmacies don't routinely maintain Kristalose inventory.
Patients in urban areas with many pharmacy options generally have better luck finding Kristalose. In rural areas or at smaller pharmacies, you may need to request a special order (typically 1–3 business days). Generic lactulose liquid is widely available at virtually all pharmacies.
If you're having trouble finding Kristalose in stock near you, medfinder can help — it contacts pharmacies on your behalf to check current inventory and texts you the results, saving you hours of frustrating phone calls.
Kristalose (lactulose) is not a controlled substance, so it can be prescribed by any licensed healthcare provider without special DEA authorization or additional credentialing. This makes it widely accessible through a variety of care settings.
Primary Care Physicians (PCPs) — family medicine and internal medicine
Gastroenterologists
Hepatologists (for lactulose use in liver disease management)
Geriatricians
Nurse Practitioners (NPs) and Physician Assistants (PAs)
Kristalose can also be prescribed via telehealth in all 50 states, since it carries no controlled substance restrictions. Platforms such as Teladoc, MDLive, and PlushCare can typically evaluate and prescribe within hours for chronic constipation patients.
No. Kristalose (lactulose) is not a controlled substance. It has no DEA scheduling designation (Schedule N/A) and has no known potential for abuse, addiction, or dependence. No special DEA registration or prescribing authorization is required to prescribe it.
This means Kristalose can be prescribed by any licensed prescriber — including primary care physicians, nurse practitioners, physician assistants, and telemedicine providers — without any additional regulatory requirements. There are no restrictions on refills based on controlled substance scheduling.
The most common side effects, occurring in approximately 20% of patients, include:
Gas / flatulence
Bloating and abdominal discomfort
Stomach cramps
Nausea
Belching
Mild diarrhea (usually from too-high doses)
Severe or persistent diarrhea
Dehydration (extreme thirst, dizziness, dark urine)
Electrolyte imbalances — hypokalemia (low potassium), hypernatremia (high sodium)
Allergic reaction (hives, difficulty breathing, facial swelling — seek emergency care)
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Generic Lactulose Solution (Constulose, Enulose, Generlac)
Same active ingredient as Kristalose in liquid syrup form. Therapeutically identical at significantly lower cost ($8–$15 with GoodRx). Best option when cost or availability of brand is an issue.
MiraLAX (Polyethylene Glycol 3350)
OTC osmotic laxative. Works similarly but without fermentation-related gas/bloating. Does not treat hepatic encephalopathy. Available without prescription.
Senna (Senokot)
OTC stimulant laxative. Faster-acting than lactulose (6–12 hours). Best for short-term or acute constipation relief. Not for long-term use.
Bisacodyl (Dulcolax)
OTC stimulant laxative. Available as tablets (6–12 hr onset) or suppositories (1 hr onset). Good for short-term bridging while seeking Kristalose.
Psyllium Husk (Metamucil)
OTC bulk-forming laxative/fiber supplement. Gentle and suitable for chronic use. Best for mild constipation or regularity maintenance.
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Non-absorbable antacids (aluminum hydroxide, calcium carbonate, sodium bicarbonate)
moderateMay inhibit the desired lactulose-induced drop in colonic pH, reducing effectiveness. Separate doses by at least 2 hours.
Warfarin (Coumadin)
moderateLactulose may enhance anticoagulant effect of warfarin. Monitor INR closely when starting, stopping, or changing dose of lactulose.
Dichlorphenamide (Keveyis)
majorBoth drugs can decrease serum potassium; combination may cause additive metabolic acidosis. Modify therapy and monitor electrolytes closely.
Other laxatives (MiraLAX, senna, bisacodyl, magnesium products)
moderateAdditive laxative effects increase risk of severe diarrhea, dehydration, and electrolyte imbalances. Avoid concurrent use without medical supervision.
Diuretics (furosemide, hydrochlorothiazide)
moderateAdditive potassium-lowering effect, especially if lactulose causes diarrhea. Monitor potassium levels in patients on both medications.
Kristalose is an effective, well-established treatment for chronic constipation. The brand-name powder packet formulation is especially valuable for patients who need precise dosing or have difficulty managing liquid medications. It is not a controlled substance, has minimal systemic absorption, and can be used long-term with appropriate monitoring.
The main challenges with Kristalose in 2026 are cost and availability. At retail prices of $307–$385/month, it is not affordable without savings programs. The Cumberland Pharmaceuticals manufacturer coupon can reduce this to as low as $5/month for eligible patients. Generic lactulose liquid is a therapeutically equivalent and much cheaper alternative for patients who don't specifically need the powder packet format.
If you're struggling to find Kristalose at your pharmacy, medfinder can help you locate which pharmacies near you have it in stock — without you having to call each one yourself.
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