The present invention relates to extracts from Galdieria sp., their preparation and their use in cosmetic compositions, particularly for topic applications in skin and hair care. The invention in based on the finding that Galdieria extract stimulates lysosomal activity and increases LC3B protein in keratinocytes, and has iron binding properties. Galdieria extract is useful in activating autophagy in human skin, e.g. photo-aged skin.
