Accutane (Isotretinoin) works by dramatically shrinking your skin's oil glands and cutting sebum (oil) production by up to 90%, which eliminates the root cause of severe acne.

What Accutane Does in Your Body

To understand how Isotretinoin works, it helps to understand what causes severe acne in the first place.

Acne forms when three things happen at once: your oil glands produce too much sebum, dead skin cells clog your pores, and bacteria (Cutibacterium acnes) multiply inside those clogged pores, triggering inflammation. Most acne treatments target only one of these factors — antibiotics kill bacteria, topical retinoids help unclog pores, and benzoyl peroxide does a bit of both.

Isotretinoin goes after all of them at once. Think of it like this: if acne is a fire, most medications are trying to blow out the flames. Isotretinoin cuts off the fuel supply.

Here's what it does, step by step:

1. Shrinks Oil Glands

Your skin has tiny oil-producing glands called sebaceous glands. In people with severe acne, these glands are often overactive and oversized. Isotretinoin physically shrinks these glands — in some cases by up to 90%. Less gland tissue means dramatically less oil production.

This is the most important thing Isotretinoin does, and it's why the medication can produce results that last long after you stop taking it. You're not just suppressing the glands temporarily — in many patients, they stay smaller permanently.

2. Slashes Sebum Production

With smaller oil glands comes a massive drop in sebum output. Sebum is the oily substance that, in excess, clogs pores and creates the environment where acne bacteria thrive. By cutting sebum production by up to 90%, Isotretinoin removes the primary raw material that feeds the acne cycle.

This is also why dry skin and dry lips are the most common side effects of Accutane — your skin is producing far less oil than it normally would.

3. Normalizes Skin Cell Turnover

In acne-prone skin, dead skin cells don't shed properly. Instead, they clump together and plug up hair follicles, creating comedones (whiteheads and blackheads) that can become inflamed. Isotretinoin normalizes this process — called follicular keratinization — so dead cells shed cleanly instead of clogging pores.

Think of it like unclogging a drain and keeping it clear. Other retinoids (like Tretinoin or Adapalene) do this topically at the skin's surface, but Isotretinoin does it systemically from the inside out.

4. Reduces Acne Bacteria

With less sebum to feed on and fewer clogged pores to hide in, Cutibacterium acnes populations drop significantly. Isotretinoin doesn't kill bacteria directly like an antibiotic does — it destroys their habitat. No oil, no clogged pores, no place for bacteria to thrive.

5. Calms Inflammation

Isotretinoin also has anti-inflammatory effects, reducing the redness and swelling that characterize nodular and cystic acne. The exact mechanism isn't fully understood, but researchers believe it involves changes in gene expression through retinoid receptors in your cells.

How Long Does Accutane Take to Work?

Most patients start seeing noticeable improvement within 4 to 8 weeks, though it varies:

• Weeks 1-4: An initial breakout ("purge") is common as the medication pushes existing clogs to the surface. Dryness begins.
• Weeks 4-8: New breakouts start to slow down. Skin becomes noticeably less oily.
• Weeks 8-16: Significant clearing in most patients. Existing lesions heal.
• Weeks 16-20: Final stages of treatment. Most patients are substantially or fully clear.

A full course is typically 15 to 20 weeks, with a cumulative target dose of 120-150 mg/kg. Your dermatologist may adjust the timeline based on your response. For more on dosing, see our Accutane overview.

How Long Do Results Last?

This is what sets Isotretinoin apart from every other acne treatment. For many patients, one course is enough for long-term or permanent clearance. Studies show that:

• About 60-80% of patients remain clear or have only minor acne after completing one course.
• Around 20-40% of patients may need a second course, usually because of a relapse months or years later.
• Repeat courses are generally just as effective as the first.

The long-lasting results happen because Isotretinoin doesn't just suppress symptoms — it physically restructures the oil glands that cause severe acne. Most other treatments only work while you're taking them.

What Makes Accutane Different from Other Acne Medications?

Here's how Isotretinoin compares to common alternatives:

• Topical retinoids (Tretinoin, Adapalene) — These work on the skin's surface to unclog pores and reduce inflammation. They're effective for mild to moderate acne but can't match Isotretinoin's ability to shrink oil glands and produce lasting results for severe cases.
• Oral antibiotics (Doxycycline, Minocycline) — These kill acne bacteria and reduce inflammation, but acne often returns after stopping them. They also carry the risk of antibiotic resistance with prolonged use. Note: tetracyclines cannot be taken with Isotretinoin.
• Spironolactone — An anti-androgen that reduces hormonal acne in women. Effective for its niche but works through a completely different mechanism and doesn't address the oil gland changes that Isotretinoin achieves.
• Benzoyl peroxide — An OTC topical that kills bacteria and unclogs pores. Useful for mild acne but not in the same league as Isotretinoin for severe nodular cases.

Final Thoughts

Isotretinoin is unique because it attacks severe acne from multiple angles simultaneously — shrinking oil glands, cutting sebum production, normalizing skin cell turnover, reducing bacteria, and calming inflammation. No other acne medication does all of this at once, which is why it produces results that often last long after treatment ends.

The trade-off is a demanding treatment course: finding a prescribing doctor, iPLEDGE enrollment, monthly blood work, and managing side effects for 4-5 months. For patients with severe acne that hasn't responded to anything else, it's often worth it.

Ready to start? Medfinder can help you find Accutane in stock near you.