Flying With Vitamins, Supplements & Protein Powder: Full Guide

Travelling with supplements is almost always straightforward — but a few rules and screening realities are worth knowing before you pack. Here is what applies in the US, EU, and UK for the most common supplements travellers carry.

The Core Rules

Liquids rule applies to pre-mixed drinks. Pre-mixed protein shakes, liquid amino acids, or any fluid supplement are subject to the standard liquid restriction: 100 ml maximum per container in a single transparent 1-litre bag in the EU and UK; 3.4 fl oz (100 ml) per container in the US. Buy or mix your shakes after security, or put larger bottles in checked luggage.

Powders: no legal ban, but size matters. There is no international ban on carrying supplement powders. However:

• The US TSA recommends keeping powdered substances in containers under 12 oz (approximately 350 ml) in carry-on. Larger amounts may be separated and subjected to additional X-ray screening. They are not confiscated — just slower.
• The UK and EU have no specific powder size guidance beyond general screening rules.
• Australia introduced powder restrictions of 350 g per container for international departures in 2018.

Solid supplements: no restrictions anywhere. Protein bars, gummies, capsules, tablets, and electrolyte tablets are solid food or medicine-adjacent items. No country restricts quantity in carry-on or checked luggage.

Supplement-by-Supplement Rules

Supplement	Carry-On Status	Notes
Vitamins and capsules	Allowed, any quantity	No restrictions globally
Protein powder (dry)	Allowed	Keep containers under 350 ml for smooth US screening
Creatine (white powder)	Allowed	Original labelled container strongly recommended
Pre-workout (powder)	Allowed	May trigger X-ray review; original container helps
Pre-mixed shakes (liquid)	Liquids rule applies	100 ml max in cabin; larger bottles must be checked
Protein bars	Allowed, any quantity	Solid food, no restriction
Electrolyte tablets	Allowed, any quantity	No restriction
Melatonin	Allowed	Supplement not medicine; no special rules anywhere
Collagen powder	Allowed	Same rules as protein powder
Creatine in capsule form	Allowed, any quantity	Capsule form avoids all powder screening questions
Insulin pens and auto-injectors	Allowed with documentation	Declare at security; medical documentation recommended

Why Creatine Attracts Screening

Creatine is a white crystalline powder. At an X-ray checkpoint, a large tub of unlabelled white powder looks the same as many other substances that security staff are trained to flag. The solution is simple: keep creatine in its original, clearly labelled container. A tub of ON Creatine with the label intact will pass without any issue. Decanted creatine in a plain bag or unmarked bottle may cause a secondary inspection and a delay. It will not be confiscated, but it may slow you down.

The Checked Luggage Alternative

If you are travelling with a full month of supplements — multiple protein tubs, creatine, BCAA, pre-workout, and vitamins — checked luggage is the practical choice:

• No powder-size considerations
• No liquid rules apply to supplements in the hold
• Heavier items stay out of your carry-on weight allowance
• Original containers have room to breathe without fitting into a personal item

The only exception: if you are on a tight supplement schedule (medication-grade timing) or travelling with expensive supplements you would not want to lose to a lost bag, keep a 2–3 day supply in your carry-on and check the rest.

International Travel Considerations

Controlled substances: Some supplements contain ingredients that are classified as controlled substances in certain countries. SARMs, certain nootropics, and some pre-workouts with stimulants may be illegal to import. Check the rules for your destination country before packing — this goes beyond aviation security and into customs law.

Melatonin: Melatonin is freely available and unrestricted in the US, Canada, and the UK. In some EU countries (Germany, France, Netherlands), melatonin above certain doses is classified as a medication requiring a prescription. For personal use quantities, this is rarely enforced at customs for travellers, but be aware of the distinction if you are carrying large quantities.

Protein powders in Australia and New Zealand: Both countries have strict biosecurity rules about food products. Commercially sealed, factory-packaged protein powders from reputable brands are generally cleared without issue. Homemade or loose powder may be questioned by biosecurity at arrival.

Packing Tips

• Use travel-size supplement packets (single-serve sachets) for carry-on trips — they weigh less and remove any powder-volume questions
• Place all powder supplements together in one external pocket for easy access during security screening
• A small zip-lock bag of capsules for 1–2 weeks is the lightest and easiest format for vitamins
• If you are flying via the US with powders over 350 ml, pack them on top of your bag so they are easy to remove for separate screening without unpacking everything else