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Guaifenesin is an expectorant that thins mucus to help clear chest congestion, and a pharmacy may compound it when a prescriber orders it.
Guaifenesin is an expectorant. It thins the mucus in the air passages so it is easier to cough up, which helps relieve chest congestion, but it does not treat the cause of symptoms or speed recovery. StatPearls notes it was approved by the FDA as an expectorant in 1952. It is sold without a prescription as tablets, capsules, extended-release tablets, dissolving granules and syrup, alone and in combination cough and cold products. Mucinex extended-release tablets, for example, are labeled to help loosen phlegm and thin bronchial secretions to make coughs more productive. A prescriber might order guaifenesin compounded in a strength, dosage form or vehicle that is not manufactured, or without a specific excipient. Compounded preparations are not FDA-approved and require a prescription.
Guaifenesin has no boxed warning. The Mucinex label says not to use it in children under 12 and to ask a doctor first if you have a persistent or chronic cough, such as from smoking, asthma, chronic bronchitis or emphysema, or a cough with too much phlegm. Stop and ask a doctor if a cough lasts more than 7 days, comes back, or comes with fever, rash or a persistent headache, because these can be signs of a serious illness. Extended-release tablets should not be crushed, chewed or broken. MedlinePlus lists headache, nausea and vomiting as possible side effects and notes that dissolving granules may contain aspartame, which matters for people with phenylketonuria. If pregnant or breastfeeding, ask a health professional before use; LactMed says guaifenesin has not been studied in breastfeeding and advises avoiding high-alcohol products while nursing. Talk to your prescriber or pharmacist about side effects.
StatPearls describes guaifenesin as an expectorant that increases the volume of respiratory tract fluid and reduces mucus viscosity. It is well absorbed from the small intestine, has a mean volume of distribution of about 116 L, and is metabolized in the liver by oxidation and demethylation to inactive metabolites, including beta-(2-methoxyphenoxy)-lactic acid, that are excreted in urine. Labeled OTC use (Mucinex): helps loosen phlegm and thin bronchial secretions to make coughs more productive, for adults and children 12 and older. Dosing is per prescriber. Reassess patients whose cough persists beyond a week, recurs, or occurs with fever, rash or persistent headache. LactMed considers harm to a nursing infant unlikely with usual maternal doses, especially after 2 months of age, though no milk data exist.
Compounded at Bayview
Patient guides for the preparations we make most often. Each one is compounded to order and requires a prescription.
We do not have a patient page for this ingredient yet. That does not mean we cannot make it. Bayview compounds this ingredient to a prescriber's order, and our full compounding formulary lists every preparation we make. Viewing the formulary requires a prescriber account.
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Every preparation in our formulary that contains this ingredient. Strength, base and dose form are set by the prescription.
Other salt forms of this molecule, and ingredients commonly compounded alongside it.
This page describes an active pharmaceutical ingredient, not a finished drug product. Bayview Pharmacy compounds preparations containing it only on a prescriber's order for an individual patient.
Compounded preparations are not FDA-approved, and the FDA has not evaluated them for safety, effectiveness, or manufacturing quality. Nothing on this page is a claim that any preparation is effective for any condition.
A valid prescription is required. Availability depends on Bayview's licensure in your state. This page is general information, not medical advice. Discuss your situation with a licensed healthcare provider.
Our pharmacists work with prescribers to build preparations around a patient's dose, form and tolerances. Ask us what is possible with this ingredient.
