L-Tryptophan supports mood, sleep, and relaxation by providing the amino acid used to form serotonin and melatonin, helping you settle into a calmer routine and sleep more peacefully. Each capsule delivers a steady supply of L-tryptophan, the building block for serotonin and melatonin production, supporting easier wind downs and more restful nights. Source Naturals has built a reputation for quality supplements. It does this through careful sourcing and reliable products.

Available Sizes & Variants:

60 capsules - convenient daily bottle for ongoing support.

Benefits & Features:

• Promotes a calmer mood and helps you wind down after a busy day.
• Supports restful sleep by providing the building block for serotonin and melatonin production.
• Designed for daily use, it integrates easily into evening routines and complements a balanced lifestyle with simple, reliable dosing that supports ongoing mood balance and relaxation.
• Active ingredient is L-tryptophan, the amino acid involved in serotonin and melatonin synthesis for mood and sleep support.
• Quality you can trust, with dependable sourcing.

Source Naturals has carved a name in the wellness space with dependable, pure amino acid supplements, and this L-Tryptophan formula stays true to that ethos. The l tryptophan benefits come from its role in serotonin and melatonin production, which can support mood and sleep. Capsules are straightforward, making it easy to fit into evening routines. Ingredients include gelatin, microcrystalline cellulose, dibasic calcium phosphate, colloidal silicon dioxide and magnesium stearate, kept stable for everyday use, and it sits among the reliable options like perfect amino tablets.

Iron (naturally occurring), L-Tryptophan, Gelatin (capsule), silica, magnesium stearate, dibasic calcium phosphate, and microcrystalline cellulose.

• GTIN: 21078019848
• Manufacturer: Source Naturals
• Categories: New ArrivalsSource NaturalsTryptophan
• Best buy: 6 - 24 months+

United Kingdom Shipping:

Orders placed by 2pm (Monday to Friday) are dispatched the same day. Orders placed after 2pm will be dispatched the next working day.

Free shipping on orders over £50 to the UK.

Returns: Our products are meant to make you feel healthy and at your best. If you need to return your item, you can do so free of charge within 30 days in the same original and unopened packaging. Subject to T&C's.

Take 1 capsule three times a day between meals, ideally with fruit juice. For restful sleep, take 3 capsules before bedtime. As a dietary supplement\, take 1 tablet daily\, preferably with meals\, or as directed by your health care practitioner. Consider taking this product in combination with NOW Thyroid Energy\, L-Tyrosine and Organic Virgin Coconut Oil.

These tablets are smaller (and easier to swallow) than most Kelp tablets\, as they contain less filler.

Please consult the product packaging for accurate instructions on how to use the product.

The Active Ingredient Is: L-Tryptophan

L-Tryptophan is an essential amino acid used by your body to help form serotonin and melatonin, hormones linked to mood and sleep regulation.

This form is an amino acid you can source and prep for supplement use to back up its role in serotonin and melatonin synthesis.

What Does L-Tryptophan Do?

L-Tryptophan helps support the normal production of serotonin and melatonin, backing mood regulation and sleep timing as part of the body’s normal function.

This links to standard physiological pathways recognised by NHS and EFSA that involve tryptophan in producing these hormones, without implying disease outcomes.

This product is not meant to diagnose, treat, cure, or prevent any disease.

Welzo's partnership criteria emphasise reliability, transparency and robust quality controls. Source Naturals meets these standards as a well recognised name in high‑quality supplements and as part of the established Nutraceutical Corporation, giving us confidence in their industry standing and heritage. The brand’s reputation for delivering dependable formulations aligns with our commitment to expert curation and patient safety, a view reinforced by our team of medical experts.

Product quality is underpinned by Source Naturals’ consistency in formulating L‑Tryptophan at a 500 mg per capsule dose, designed to support relaxation, restful sleep and mood assistance as described in their product guidance. Their approach fits our strict sourcing and purity standards, which you can explore through how we verify ingredient quality.

From a product fit perspective, this brand stands out for offering a simple, well‑characterised amino acid supplement that supports the intended category without unnecessary additives. Our evaluation process weighed brand track record, manufacturing philosophy and third‑party assurances, leading to a confident recommendation that Source Naturals is well placed to partner with Welzo for L‑Tryptophan.