There are different levels of oily scalp to contend with, on average a person would need to shampoo their hair every 2, maybe 3 days. The products you use definitely contribute to the feeling of heaviness on the hair.
If the problem is naturally occurring oils and not product, then you want to Rebalance oily skin.
Alfaparf Semi DiLino Balancing Low Shampoo helps to rebalance, normalise, prevent as well as slowly shrinking the sebaceous gland.
Its recommended this is also used with Energising Tonic.
What if it's not the sebaceous gland that is the issue and simply a buildup of product, or just products that are simply not suited to your hair type.
Here is a couple of tips I find can help:
Fine/normal hair - like mine can be very unforgiving when it comes to products. I have found the best option for me is clear and not creamy shampoos. I also don't use conditioner in the shower YES, I REALLY SAID THAT! Through very clever and targeted marketing throughout the years we have all been brought up to believe shampoo/condition is the only way to go. Not necessarily the only option.
My fine/normal super soft hair absolutely does not need to be softened any more so, I skip my in-shower condition and opt for a nice detangling product afterwards. About once every 2 weeks I pop in a treatment mask in the shower which helps to hydrate and keep my hair in top condition.