Colonoscopy Prep Cost: Prescription Kits, GoodRx Prices, and OTC Alternatives
The prep prescription your GI office calls in after scheduling is easy to overlook until you’re standing at the pharmacy counter. Some cost $20. Some cost $300. The difference has nothing to do with how well they work.
Here’s the real price landscape for every major colonoscopy prep, how GoodRx changes the math, and whether the DIY Miralax option your doctor might approve could save you the most of all.
The Main Prescription Prep Options
GoLYTELY / NuLYTELY (Polyethylene Glycol 3350)
Generic PEG solutions are the workhorses of colonoscopy prep. You drink large volumes (typically 1–4 liters) over a few hours the evening before and/or morning of the procedure.
- Retail price: $40 – $80 at most pharmacies
- GoodRx price: As low as $18 – $35 at major chains
- Insurance: Usually covered as a Tier 1 or Tier 2 generic; typical copay $5–$30
These are ASGE-endorsed as effective, well-studied preparations. They’re not glamorous, but they work.
Suprep (Sodium Sulfate / Potassium Sulfate / Magnesium Sulfate)
Suprep is a lower-volume option — two 6-ounce doses mixed with water. The generic version (sutab is a different formulation) became available around 2021.
- Brand Suprep retail: $100 – $180
- Generic (sulfate) retail: $60 – $120
- GoodRx generic price: $45 – $80 depending on pharmacy
- Insurance: Brand often requires prior auth; generic usually covered at Tier 2
Clenpiq (Sodium Picosulfate / Magnesium Oxide / Citric Acid)
Clenpiq comes in two small bottles (160mL each). It’s popular for its lower volume, but it’s brand-only with no generic currently available.
- Retail price: $220 – $320
- GoodRx: Minimal discount on brand-only products; $190 – $280 typical
- Manufacturer coupon: Ferring Pharmaceuticals offers patient savings cards — bring down to $30–$50 for commercially insured patients who qualify
- Insurance: Often requires prior authorization; some formularies exclude it
Sutab (Sodium Sulfate / Sodium Chloride / Potassium Chloride)
Sutab is a tablet formulation — 12 tablets taken in two divided doses with water. No mixing, no large-volume liquid.
- Retail price: $120 – $200
- GoodRx: $90 – $160
- Insurance: Tier 3 on most formularies; prior auth common
| Prep Product | Retail Price | GoodRx Price | Insurance Copay (typical) |
|---|---|---|---|
| GoLYTELY/NuLYTELY (generic) | $40 – $80 | $18 – $35 | $5 – $30 |
| Suprep (generic) | $60 – $120 | $45 – $80 | $20 – $50 |
| Clenpiq (brand) | $220 – $320 | $190 – $280 | $50 – $150 (with coupon) |
| Sutab | $120 – $200 | $90 – $160 | $30 – $100 |
| Miralax + Gatorade (OTC) | $22 – $30 | N/A (OTC) | Not covered |
The OTC Option: Miralax + Gatorade Split-Dose
The ACG (American College of Gastroenterology) included the Miralax split-dose prep in its 2021 colorectal cancer screening guidelines as an acceptable preparation for appropriate patients. Here’s what it costs:
- 1 bottle of Miralax (238g): $17 – $22 at most pharmacies
- Two 32oz bottles of Gatorade (yellow or white — no purple or red): $4 – $6
- Total cost: approximately $22 – $28
The protocol involves mixing the Miralax into the Gatorade and drinking half the evening before, half the morning of the procedure. Your GI physician must approve this approach for you specifically — it’s not appropriate for all patients (particularly those with renal issues or constipation).
But it’s the cheapest option available, and for many patients it’s no harder than the prescription alternatives.
How to Ask Your Doctor About the OTC Prep Option
Call your GI physician’s office after your procedure is scheduled and say: “I’ve read that the Miralax split-dose prep is an ACG-approved option. Am I a candidate for that instead of the prescription prep? I’m trying to minimize out-of-pocket costs.”
If you’re average-risk and medically straightforward, many GI offices will approve this approach. Some actually prefer it. Ask before the prescription gets called in — it’s much easier than trying to cancel a prescription you’ve already picked up.
Using GoodRx for Prep Medications
GoodRx works by presenting a discounted price from participating pharmacy benefit managers (PBMs) at the point of sale. For colonoscopy preps:
- Search for your specific prep medication at goodrx.com or the GoodRx app
- Compare prices at pharmacies near you — they vary significantly (Costco and Walmart often lowest, CVS and Walgreens often highest)
- Show the GoodRx coupon or barcode at the pharmacy when picking up
- Do not use your insurance if GoodRx is cheaper (and you can’t combine them)
The savings are most dramatic on brand-name products and least impactful on generics already priced below $30.
What About the Low-Residue Diet Before Prep?
Most colonoscopy prep instructions include a low-fiber/low-residue diet for 1–3 days before the procedure. Some GI offices now use a same-day morning prep protocol with a clear liquid diet only the day before.
Either way, the diet modification itself is low cost. You’re avoiding high-fiber foods (raw vegetables, whole grains, seeds) and switching to white rice, eggs, chicken, fish, and cooked vegetables. The cost difference from your normal diet is minimal — maybe $10–$20 if you’re buying different foods than usual.
The Total Prep Cost Picture
Add it up: a GoLYTELY prep with GoodRx runs $20–$35. The Miralax option runs $25. Clenpiq without a manufacturer coupon runs $200+. The choice of prep can vary your out-of-pocket by $200 — for a product that serves an identical function. Ask your GI physician which preps they’re comfortable with and choose the most affordable one they approve.
For the full picture of colonoscopy costs beyond prep, see colonoscopy cost for the complete billing breakdown.