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5-HTP is the direct precursor to serotonin, which is a key neuromodulator for maintaining upper airway muscle tone during sleep. Animal studies show that blocking serotonin activity can induce snoring and upper airway collapse, reversed when serotonin returns. A 2024 review in MDPI's IJMS confirmed the central role of the 5-HT signaling pathway in OSA/snoring pathophysiology, and a 2023 observational study found negative correlations between blood serotonin levels and obstructive apnea and oxygen desaturation scores.

L-Tryptophan was studied in a 1983 PubMed study (Schmidt HS, Physiologist) in 15 patients with sleep apnea (12 obstructive), showing significant improvement in obstructive sleep apnea at an average dose of 2500 mg at bedtime, but not central apnea. It is a serotonin precursor, and serotonin is critical for maintaining upper airway muscle tone during sleep. L-Tryptophan has also been included in patented snoring treatment compositions.

Lavender essential oil was one of the components in the Prichard 2004 double-blind study blend (140 adult snorers) in which 82% of bed partners reported reduced snoring with the essential oil spray versus 44% with placebo. Lavender promotes muscular relaxation and sleep quality through calming of the nervous system. A 2020 RCT comparing lavender and peppermint aromatherapy confirmed improved sleep quality in cardiac patients.

Sweet marjoram (Origanum majorana) essential oil was included in the Prichard 2004 double-blind snoring study blend and is widely cited as an anti-snoring essential oil. It has antispasmodic and muscle-relaxant properties that may reduce pharyngeal tissue vibration. Marjoram's expectorant action can also help clear sinus and nasal congestion contributing to snoring.

Melatonin has been studied in patients with obstructive sleep apnea (OSA), the primary disorder underlying most snoring. A 2024 randomized double-blind placebo-controlled trial found 10 mg melatonin improved sleep latency, reduced mid-night wakeups, and enhanced sleep quality in OSA patients. Melatonin secretion is significantly altered in approximately 25% of OSA patients. It has also been included in patented snoring treatment formulations alongside L-tryptophan.

A randomized placebo-controlled trial in 20 adults with obstructive sleep apnea found that 600 mg NAC given three times daily for 30 days significantly reduced AHI, apnea-related arousals, oxygen desaturation, daytime sleepiness, and snoring (relative snore time and number of snore episodes). NAC is an antioxidant that mitigates oxidative stress and sympathetic nervous system excitation from intermittent hypoxia.

Peppermint essential oil was a component of the blend tested in a 2004 double-blind controlled study (Prichard, Phytotherapy Research) of 140 adult snorers from a snoring clinic, in which 82% of bed partners reported reduced snoring with the essential oil spray versus 44% with placebo. Its active compound menthol acts as a decongestant and has anti-inflammatory properties on nasal passages and upper airways. Aromatherapy with peppermint has also been studied for improving sleep quality in cardiac patients (randomized controlled trial, 2020).

Thyme essential oil was one of the components in the Prichard 2004 double-blind study (140 adult snorers) where the essential oil blend spray reduced snoring in 82% of users' bed partners versus 44% in placebo. Thyme's active compound thymol has antispasmodic and respiratory-clearing properties. Thyme is traditionally used in folk medicine for respiratory conditions and has become popular specifically for snoring.

A clinical study found that a 500 mg intravenous dose of vitamin C improved endothelial dysfunction in OSA patients (Am J Respir Crit Care Med, 2006). A combination of vitamin C (100 mg) and vitamin E (400 IU) twice daily for 45 days reduced apneic episodes and improved sleep quality in 20 men with OSA on CPAP. Animal models confirm vitamin C reduces oxidative and carbonyl stress in OSA. A UK Biobank cohort study of 68,221 participants examined the association between dietary vitamin C and sleep apnea.

Vitamin E, in combination with vitamin C (100 mg C + 400 IU E, twice daily, 45 days), was shown in a controlled study of 20 men with OSA on CPAP to reduce apneic episode frequency, improve sleep quality, and reduce daytime sleepiness. Animal studies confirm vitamins C and E together reduce oxidative and carbonyl stress from intermittent hypoxia in OSA models. Reduced vitamin E levels have been measured in OSA patients compared to controls.

Chamomile has a long tradition of use for snoring and sleep disorders through its muscle-relaxing and sedating effects on the respiratory airways. Traditional herbal medicine across Europe prescribes chamomile tea before bed to soothe throat tissues and reduce inflammation. It appears in essential oil blends recommended for snoring, including alongside thyme and marjoram in traditional practice.

Garlic has been used traditionally to reduce snoring by clearing the respiratory tract and reducing mucus buildup in nasal passages. Traditional practice involves chewing garlic cloves or consuming garlic before bedtime. It has anti-inflammatory and decongestant properties that may reduce upper airway obstruction contributing to snoring.

Valerian root (Valeriana officinalis) has a traditional history of use for snoring through its sedative and antispasmodic effects on respiratory tract tissue and sleep quality improvement. Traditional folk medicine prescribes valerian for snoring combined with thyme or fenugreek. Valerian essential oil is included in commercial anti-snoring essential oil formulations alongside lavender and chamomile.