Yes, you can absolutely put your toiletry bag in your checked suitcase, and in 2026, this is actually the recommended way to pack full-sized liquids. Unlike carry-on bags, which are strictly limited by the "3-1-1" rule (3.4oz/100ml containers in one quart-sized bag), checked luggage has no limit on the size or quantity of liquids like shampoo, lotion, and large tubes of toothpaste. The only major restrictions are for hazardous materials; for example, you cannot pack flammable liquids or aerosols that are not intended for personal grooming. To prevent a "shampoo explosion" caused by cabin pressure changes, "pro" travelers suggest tightening all caps, placing bottles inside individual zip-top bags, and nesting the toiletry bag in the center of the suitcase surrounded by soft clothing to act as a cushion. If you are packing a toiletry bag in a carry-on, however, it must still be a clear, quart-sized bag, and any individual item over 3.4oz will be confiscated at security unless you have a specific medical or infant-care exemption.