Oscar Pistorius' PR firm said the substance found in his bedroom is Testis compositum, which aids "muscle recovery", according to the Associated Press.
The 'Blade Runner' is currently on bail and local media reports suggest he requested the memorial service to allow him to grieve at his partner's death.
Pistorius' family members will attend the private Pretoria service which will take place at the house of Arnold Pistorius, Oscar's uncle.
The South African media have been asked to respect the Pistorius family's privacy.
Oscar Pistorius faces at least four random tests for drugs and alcohol in coming months to ensure he is complying with bail terms, a South African prison service official has said.
The Paralympic star was granted bail on Friday ahead of his trial for the murder of his girlfriend Reeva Steenkamp on 14 February.
Earlier today, Pistorius checked in with a probation officer at Pretoria magistrate's court in compliance with bail conditions set out last week.
He was also ordered to surrender his two passports, post bail of 1million rand (£74,000), and refrain from drinking alcohol until his case resumes on 4 June.
CCTV footage has emerged of Reeva Steenkamp arriving at the home of Oscar Pistorius hours before her death.
Steenkamp is shown smiling as she drives into the luxury gated community where Pistorius lived.
The video was shown on South Africa's M-Net show Carte Blanche last night.
Oscar Pistorius' spokeswoman said he has reported to authorities in Pretoria as part of his bail conditions.
Lunice Johnston told the Associated Press that Pistorius has visited correctional officers, but did not reveal where the meeting took place.
Pistorius, who was released on bail Friday, is accused of premeditated murder following the death of his girlfriend, Reeva Steenkamp, in the early hours of February 14.
Prosecutors claim the couple argued before Steenkamp was killed. Pistorius says he mistook Steenkamp for an intruder and that the shooting was an accident.
I am outside Brooklyn Police Station in Pretoria.
Oscar Pistorius must come here today to sign a register as part of his bail conditions.
Oscar Pistorius is due to attend a police station this morning as part of his bail conditions.
Reeva Steenkamp's parents have given an interview to South African television they hope Oscar Pistorius "might just come out with the honest truth" about what happened in the runner's home in Pretoria.
– Barry Steenkamp
It’s only Oscar [and] Reeva that know the true story. All I want is that he must just come out with the honest truth.
– June Steenkamp
We can’t come to terms with this. This is going to be for ever.
Pistorius is to attend a police station this morning as part of his bail conditions.