Turmeric, has been studied on numerous occasions to improve joint pain, there are also some studies that it's good for your skin and digestion, but most customers and Qunol turmeric themselves are more interested in promoting it's joint health benefits.
There is less evidence to support it's use to improve skin.
However, there are a lot of studies which back it's use as an accompanying treatment for arthritic joints and other injuries. For example one study showed that it outperformed ibuprofen for pain relief on knees [1].
Meta analysis of multiple turmeric studies suggests that most studies using curcumin complex at doses over 500mg a day do in fact relieve joint pain[2]. And both harvard [3] and the arthritis foundation [4] list curcumin complex as being effective, although all specify that it's the curcumin that does the work.
Qunol liquid capsules (only 22% curcumin and 1000mg)
The liquid capsules only contain 200mg of curcumin and as we've already mentioned 500-1000mg of curcumin is required to be effective to relieve pain in joints.
Qunol liquid turmeric
Qunol liquid turmeric does offer a full 1000mg of curcumin, which is well within the range of it being effective, so this is actually a decent product, although it is for a niche audience and quite expensive.
Qunol turmeric gummies
The gummies however are the worst offenders by far, with just 100mg of curcumin and 50mg of ginger which requires 3 grams to be effective, (outside of specific gingerol complexes like eurovita 77, which still needs 250mg). As a result the Qunol turmeric gummies are not going to be effective in the slightest.
References
1 - https://pubmed.ncbi.nlm.nih.gov/32749918/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5003001/
3 - https://www.health.harvard.edu/blog/curcumin-for-arthritis-does-it-really-work-2019111218290
4 - http://blog.arthritis.org/living-with-arthritis/anti-inflammatory-tumeric-curcumin/