Correct. the quinine amount in tonic water is not high enough to have a therapeutic effect. But, it is possible to be used prophylactically along with zinc - if you can find it. Tonic water has been used for decades as a preventative for malaria. People with diabetes need to be cautious about the added sugar. Just another word of caution though. If you take other supplements containing zinc, make sure the total does not exceed recommended amounts. The maximum recommended dosage for adults should not exceed 40mg of zinc per day; however, during times of illness or other zinc-zapping life events, you could ingest several times that amount for up to a year. Also, if a person has a history of anemia, caution should be used. Too much zinc can exacerbate anemia by reducing copper levels. Minerals in the body are always in balance. Zinc is balanced by copper - therefore, too much zinc can deplete the copper which affects hemoglobin's ability to bind oxygen among other problems. They do make zinc supplements that contain copper. Here is some good information on zinc-copper ratios. https://www.deannaminich.com/copper-to-zinc-achieving-the-right-balance/ Just some information about different forms of zinc products.  Zinc gluconate: As one of the most common over-the-counter forms of zinc, zinc gluconate is often used in cold remedies, such as lozenges and nasal sprays. Zinc acetate: Like zinc gluconate, zinc acetate is often added to cold lozenges to reduce symptoms and speed up the rate of recovery. Zinc sulfate: In addition to helping prevent zinc deficiency, zinc sulfate has been shown to reduce the severity of acne. Zinc picolinate: Some research suggests that your body may absorb this form better than other types of zinc, including zinc gluconate and zinc citrate. Zinc orotate: This form is bound to orotic acid and one of the most common types of zinc supplements on the market. Zinc citrate: One study showed that this type of zinc supplement is as well-absorbed as zinc gluconate but has a less bitter, more appealing taste.  https://www.healthline.com/nutrition/zinc-supplements#types