Switching from aluminum-based deodorants to non-aluminum alternatives and then back again generally does not cause a significant reaction for most people. However, individual reactions can vary based on skin sensitivity and specific ingredients in the products. Some people may experience irritation or changes in body odor during the transition period, especially if their skin needs to adjust to a new formulation.
If you have had a previous reaction to aluminum-based deodorants or any of the other ingredients in these products, it's important to monitor your skin for any adverse reactions when switching back. If you're concerned, consider doing a patch test by applying a small amount of the deodorant to your skin to see if you react before using it more broadly. If irritation occurs, it might be best to stick to non-aluminum products.