NAC - N-Acetylcysteine

Name: NAC - N-Acetylcysteine
Brand: Thorne
SKU: product-0190
Price: 25.00 GBP
Availability: InStock
Rating: 4.9 (41 reviews)

£25.00

Thorne NAC is a supplement providing N-Acetylcysteine, a precursor to glutathione — the body's principal intracellular antioxidant.

Supports glutathione production as a cysteine precursor
May help maintain respiratory tract mucus clearance
Studied for liver and detoxification pathway support
Relevant for those under high oxidative stress loads
Single-ingredient capsule suited to clinician-guided protocols

4.9 (41 reflections)

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ThorneNAC - N-Acetylcysteine

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About This Product.

Thorne NAC is a supplement providing N-Acetylcysteine, a precursor to glutathione — the body's principal intracellular antioxidant. By replenishing cysteine, one of glutathione's three building blocks, NAC supports the liver's capacity to neutralise oxidative stress and process metabolic waste. It is also studied for its role in maintaining healthy mucus viscosity in the airways, which is why it appears in protocols for people with recurrent respiratory congestion or those exposed to environmental pollutants.

This supplement suits people whose blood work or clinical assessment points to elevated oxidative load — heavy exercisers in prolonged training blocks, individuals with liver stress markers, or those managing chronic respiratory discomfort. It may also be relevant for anyone supporting detoxification pathways alongside dietary or lifestyle changes.

NAC is a well-characterised molecule with decades of research behind it, most notably in liver and respiratory contexts. Thorne is a brand respected in clinical practice for manufacturing rigour and ingredient quality. This formulation delivers N-Acetylcysteine as a straightforward single-ingredient capsule, which makes it straightforward to dose adjustments under clinical guidance and to stack where appropriate.

Frequently Asked.

Why take NAC rather than glutathione directly?

Oral glutathione is poorly absorbed intact; the gut breaks most of it down before it reaches cells. NAC provides cysteine, the rate-limiting precursor, which cells use to synthesise glutathione themselves. This makes NAC a more reliable route to raising intracellular glutathione levels.

Who is most likely to benefit from NAC supplementation?

People with high oxidative load — endurance athletes in heavy training, individuals with liver stress identified on blood tests, or those with recurrent respiratory congestion — are the most studied populations. It is also used in clinical settings to support detoxification protocols.

Is NAC safe to take alongside other supplements or medications?

NAC is generally well tolerated, but it can interact with certain medications, including some blood thinners and blood pressure drugs. If you are on any regular prescription medication, check with your doctor or pharmacist before starting.

How long before I notice a difference?

This depends heavily on why you are taking it. For respiratory comfort, some people notice a change within a few weeks. Measurable shifts in oxidative markers or liver enzymes are more reliably assessed via a follow-up blood panel after 6 to 12 weeks of consistent use.

Are there any side effects to be aware of?

At standard doses NAC is well tolerated by most adults. Some people experience mild nausea or gastrointestinal discomfort, particularly on an empty stomach. Taking it with food generally reduces this. At very high doses there is a small risk of headache; check the packaging and follow clinical guidance on upper intake.

Customer Reflections

Overall Sentiment

4.941 reflections

1 – 6 of 41 reflections

Solid part of my morning stack

4 months ago

Take this with breakfast alongside my omega-3s and magnesium. Been on it about eight weeks now and my energy feels steadier — hard to attribute to any one thing but I noticed less of that heavy, sluggish feeling after training. Easy to swallow, no aftertaste.

Recommended by my GP

4 months ago

Started this after a blood panel flagged some liver markers. Two months in, follow-up bloods were better. Not claiming this did everything but it was part of the protocol and I'll keep going.

5 months ago

Does what it says. Simple capsule, no fuss. Would buy again.

Good quality but the capsule count feels low for the price

5 months ago

The quality seems excellent and I do feel less congested than I did before — genuinely surprised by that. My only gripe is that 90 capsules at £24.99 runs out faster than I'd like at the suggested daily dose. Wish they did a larger bottle.

Using during marathon training block

5 months ago

Physio suggested antioxidant support for my heavy training load ahead of London. Added NAC about six weeks out. Can't say I ran a miracle time but recovery between sessions felt noticeably less grinding. Will keep in the routine post-race too.

5 months ago

Take it before bed with some magnesium. Sleep feels good, breathing feels clearer. Happy with it.

NAC - N-Acetylcysteine

About This Product.

How to Take It

Frequently Asked.

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