NAC is primarily known for its antioxidant properties, because it helps the body produce glutathione. It has been studied in very different areas, from skin health to female hormonal health.
What is NAC?
N-acetylcysteine is the acetylated form of the amino acid L-cisteína. In medicine, it has been used for decades as a mucolytic, to thin respiratory secretions, and as an antidote for paracetamol poisoning. As a dietary supplement, it is used for its role in the production of glutathione.
How does it work?
- Glutathione precursor: it provides the cysteine the body needs to produce glutathione, which protects cells against oxidative damage.
- Anti-inflammatory action: it reduces the activity of the NF-κB factor and pro-inflammatory cytokines such as IL-6, IL-8, and TNF-α.
- Mucolytic action: it breaks the bonds that give mucus its viscosity.
What does science say?
Female hormonal health
A meta-analysis of controlled trials in women with polycystic ovary syndrome observed that NAC improved ovulation and pregnancy rates compared to a placebo (Thakker 2015).
Menstrual cycle and pain
In an observational study on women with endometriosis, those who took NAC for three months reported less pain and a reduction in the size of ovarian cysts (Porpora 2013). This is a preliminary study and controlled trials are needed.
Skin
Due to its antioxidant and anti-inflammatory action, NAC has been proposed as support for acne-prone skin, as oxidative stress and inflammation are involved in its appearance. Evidence for this use is still limited.
Dosage and how to take it
- Studies have used between 600 and 1,800 mg per day.
- As a supplement, the most common dosage is 300 to 600 mg per day.
- It can be taken with or without food; take it with food if you notice digestive discomfort.
Safety and contraindications
- It is usually well tolerated. The most frequent side effects are nausea or mild digestive discomfort; its slight sulfur smell is normal.
- It is recommended to avoid it during pregnancy and breastfeeding unless indicated by a doctor.
- People with asthma or gastroduodenal ulcers should consult their doctor first.
- It can enhance the effect of nitroglycerin; if you take heart medication, consult your doctor first.
Frequently asked questions
Is NAC the same as pharmacy mucolytics?
It is the same active ingredient as some mucolytics, but as a supplement, it is used in different doses and for a different purpose: to support glutathione production.
What is NAC used for in women?
It has been studied primarily in relation to female hormonal health and cycle-related pain, always as a supplement and never as a substitute for medical supervision.
When is the best time to take it?
At any time of the day. If it upsets your stomach on an empty stomach, take it with food.
References
- Thakker D, Raval A, Patel I, Walia R. N-acetylcysteine for polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled clinical trials. Obstet Gynecol Int. 2015;2015:817849.
- Porpora MG, Brunelli R, Costa G, et al. A promise in the treatment of endometriosis: an observational cohort study on ovarian endometrioma reduction by N-acetylcysteine. Evid Based Complement Alternat Med. 2013;2013:240702.
