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

Temozolomide — sold under the brand name Temodar — is an oral chemotherapy drug used to treat brain cancer. It is the cornerstone of treatment for glioblastoma multiforme (GBM), the most aggressive and most common form of primary brain cancer in adults. Here's a comprehensive overview of what temozolomide is, what it treats, how it is taken, and what patients can expect.

What Is Temozolomide?

Temozolomide is an alkylating chemotherapy agent — a drug that works by damaging the DNA inside cancer cells, preventing them from growing and dividing. It belongs to the same class as dacarbazine (DTIC) and is a derivative of that drug. Temozolomide was first approved by the FDA in 1999 (IV form) and then for oral use in glioblastoma in 2005. The FDA issued an updated label in September 2023 under Project Renewal, adding new indications and updating dosing guidance.

Temozolomide has two important properties that make it particularly effective for brain tumors: it is taken orally (as a capsule), and it crosses the blood-brain barrier — the protective membrane that separates the brain from the bloodstream and which many chemotherapy drugs cannot penetrate.

What Conditions Does Temozolomide Treat?

Temozolomide is FDA-approved for the following indications:

• Newly diagnosed glioblastoma multiforme (GBM): Given concurrently with radiation therapy after surgical resection, then as maintenance chemotherapy for up to 6 cycles. This is the Stupp protocol, the current standard of care for GBM.
• Adjuvant treatment of newly diagnosed anaplastic astrocytoma: Added as an indication in September 2023.
• Refractory anaplastic astrocytoma: For patients who have experienced disease progression after a nitrosourea- and procarbazine-containing regimen.

Off-label, temozolomide is also used in recurrent grade 2 gliomas, advanced neuroendocrine tumors (pNETs), and aggressive pituitary adenomas, among other tumor types.

What Are the Available Forms and Strengths?

Temozolomide comes in two forms:

• Oral capsules: Available in 5 mg, 20 mg, 100 mg, 140 mg, 180 mg, and 250 mg strengths. Most patients take a combination of strengths to achieve their exact BSA-calculated daily dose.
• IV injection: A 100 mg lyophilized powder for injection, administered over 90 minutes in a clinical setting when the oral route is not feasible. The IV formulation provides equivalent drug exposure to the oral capsules.

How Is Temozolomide Dosed?

Dosing is calculated based on body surface area (BSA), which is derived from height and weight. The dose may change if you gain or lose significant weight during treatment.

For newly diagnosed GBM (Stupp protocol):

• Concurrent phase: 75 mg/m² once daily for 42–49 days alongside radiation therapy
• Maintenance phase (Cycle 1): 150 mg/m² on Days 1–5 of a 28-day cycle
• Maintenance phase (Cycles 2–6): May increase to 200 mg/m² if tolerated; 6 total maintenance cycles

How to Take Temozolomide Capsules

• Swallow capsules whole with a full glass of water — do not open, crush, or chew them.
• Take at the same time each day to maintain consistent blood levels.
• Taking on an empty stomach or at bedtime may reduce nausea.
• If you vomit after taking temozolomide, do not retake the dose — contact your oncologist.
• If a capsule is accidentally opened, avoid contact with the powder on skin, eyes, or nose.

Is Temozolomide a Controlled Substance?

No. Temozolomide is not a controlled substance and is not scheduled by the DEA. However, it is a cytotoxic chemotherapy drug available only by prescription from a licensed provider, and it requires careful medical supervision due to its effects on blood counts and immune function.

How Much Does Temozolomide Cost?

Temozolomide is a specialty medication with high retail prices. The average retail price for the most common version can exceed $3,400 without insurance or discounts. However, with a GoodRx coupon, the price can drop to as low as $112.75, and SingleCare offers certain strengths for as low as $49.98. Most insured patients pay a specialty tier copay. Generic manufacturers — including Lannett, Amneal, Sun Pharma, and Camber — provide more affordable options than brand-name Temodar.

How to Find Temozolomide at a Pharmacy Near You

Temozolomide is a specialty drug not stocked at all pharmacies. medfinder.com can call pharmacies near you to check which ones have your specific capsule strength in stock, saving you hours of phone calls before each treatment cycle.

For more detail on what to expect during treatment, see: Temozolomide Side Effects: What to Expect and When to Call Your Doctor.