SOLVED. Help me to find a fiction book, related to time travel [s]

[Tôi]

Help me to find this book. It's a story about an middle-aged doctor who voluntarily goes to an abjectly undeveloped country to help its people. In there, he meets a tribal chief who gives him ten yellow pills that allow him to go back to the past. In the past, death had separated him and his lover,who was a dolphin trainer. So this time, he uses these pills to change the past. In the end, he and his lover finally can find each other and live happily.
Thank you in advance

[Lobstergirl, au gratin]

What year did you read it? Author male or female? Any cover art or photo? Is his lover female?

[Tôi]

yes, his lover is female. I read it in 2010 , It's a pity that I don't remember anything about it cover or the author

[Adele]

I believe it is Will You Be There?

[Tôi]

Bingo !! thank you so much !!

[Adele]

You're very welcome. :-)