I have with me, partnerships with 74 influencers on Instagram (in the healthy lifestyle niche), and we are trying to decide a product to endorse next month. These influencers have highly engaged audiences that generally leads to a high conversion rate of new customers.
If you're interested, comment below with the url to your store, and in one sentence or two, tell me how your product is awesome (i.e. differentiation from competitors).
Insagram is a social media platform for sharing images so I think you should sell products for health that have attractive image such as health band, sport watch, ...
If you find it's hard to looking for a product to sell on Instagram, this writing What to Sell Online: How to Come Up With the Perfect Product Ideas would be suitable for you.
Hope it helps!