Last update Aug. 29, 2021

Nitrous Oxide


Safe substance and/or breastfeeding is the best option.

Gas with analgesic and anesthetic properties.
Used in the induction and maintenance of general anesthesia and, mixed with oxygen, for analgesia and sedation in obstetric and other painful procedures.
Administered by inhalation.

At the date of the last update, there was no available published data on its excretion in breast milk.

Its poor fat solubility and acid pKa, as well as its very fast elimination half-life (T½ of 3 minutes) make the passage of breast milk unlikely.
Its low oral bioavailability makes it difficult for the infant to pass into plasma from ingested breast milk.
The short T½ allows the mother to breastfeed again as soon as she wakes up from anesthesia, is alert and fit and able to hold her baby.

There is much experience of its use during self-administered labor ad libitum by the mother herself and no negative effects on the newborn, infant or lactation have been reported (Rooks 2011).

Nitrous oxide labor analgesia is associated with better rates of breastfeeding and exclusive breastfeeding at one week, one and three months postpartum (Zanardo 2018).

Expert authors consider the use of this medication safe during breastfeeding (Howie 2006, Hale 1999).


We do not have alternatives for Nitrous Oxide since it is relatively safe.

Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Nitrous Oxide is also known as

Nitrous Oxide in other languages or writings:


Nitrous Oxide belongs to this group or family:


Main tradenames from several countries containing Nitrous Oxide in its composition:


Variable Value Unit
Oral Bioavail. Baja - Low %
Molecular weight 44 daltons
pKa 4.65 -
Tmax 0.25 hours
0.05 hours


  1. Zanardo V, Volpe F, Parotto M, Giiberti L, Selmin A, Straface G. Nitrous oxide labor analgesia and pain relief memory in breastfeeding women. J Matern Fetal Neonatal Med. 2018 Dec;31(24):3243-3248. Abstract
  2. INSHT-Instituto Nacional de Seguridad e Higiene en el Trabajo. Gases anestésicos en ámbitos no quirúrgicos (I): sistemas de aplicación. Notas Técnicas de Prevención. 2012 Full text (link to original source) Full text (in our servers)
  3. Rooks JP. Safety and risks of nitrous oxide labor analgesia: a review. J Midwifery Womens Health. 2011 Nov-Dec;56(6):557-65. Abstract
  4. INSHT-Instituto Nacional de Seguridad e Higiene en el Trabajo. Ventilación general en hospitales. Notas Técnicas de Prevención. 2010 Full text (link to original source) Full text (in our servers)
  5. Howie WO, McMullen PC. Breastfeeding problems following anesthetic administration. J Perinat Educ. 2006 Abstract Full text (link to original source) Full text (in our servers)
  6. MSC-Ministerio de Sanidad y consumo. España. Agentes anestésicos inhalatorios. Protocolos de vigilancia específica. 2001 Full text (link to original source) Full text (in our servers)
  7. Hale TW. Anesthetic medications in breastfeeding mothers. J Hum Lact. 1999 Sep;15(3):185-94. Review. No abstract available. Abstract

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